I'm also seeing this all the time. Happens about every hour or so. This is probably the most annoying bug I have in intrepid right now. At least I've been able to get a full stack leading up to this particular assert: #1 0xb7e04a25 in _XGetXCBBuffer (dpy=0x8ec27b0) at ../../src/xcb_lock.c:101 #2 0xb7e05e83 in _XSend (dpy=0x8ec27b0, data=0x0, size=0) at ../../src/xcb_io.c:239 #3 0xb7e06042 in _XFlush (dpy=0x8ec27b0) at ../../src/xcb_io.c:258 #4 0xb7dde041 in XFlush (dpy=0x8ec27b0) at ../../src/Flush.c:41 #5 0x080ec3ac in CXWindowsEventQueueBuffer::flush (this=0x8ed7820) at CXWindowsEventQueueBuffer.cpp:249 #6 0x080ec4e3 in CXWindowsEventQueueBuffer::addEvent (this=0x8ed7820, dataID=11) at CXWindowsEventQueueBuffer.cpp:210 #7 0x0811f124 in CEventQueue::addEvent (this=0xbfd24a3c, event=@0xb72e8140) at CEventQueue.cpp:221 #8 0x081180be in CTCPSocket::sendEvent (this=0x8ed8030, type=19) at CTCPSocket.cpp:358 #9 0x08118512 in CTCPSocket::serviceConnected (this=0x8ed8030, job=0xb69118a8, read=false, write=true, error=false) at CTCPSocket.cpp:465 #10 0x0811a785 in TSocketMultiplexerMethodJob::run (this=0xb69118a8, read=false, write=true, error=false) at TSocketMultiplexerMethodJob.h:79 #11 0x08112d09 in CSocketMultiplexer::serviceThread (this=0xbfd24adc) at CSocketMultiplexer.cpp:228 #12 0x081146c3 in TMethodJob::run (this=0x8ec2090) at ../../lib/base/TMethodJob.h:63 #13 0x0811d908 in CThread::threadFunc (vjob=0x8ec2090) at CThread.cpp:152 #14 0x08132845 in CArchMultithreadPosix::doThreadFunc (this=0x8ec0008, thread=0x8ec20c8) at CArchMultithreadPosix.cpp:720 #15 0x081329ad in CArchMultithreadPosix::threadFunc (vrep=0x8ec20c8) at CArchMultithreadPosix.cpp:701 #16 0xb7c8950f in start_thread () from /lib/tls/i686/cmov/libpthread.so.0 #17 0xb7c067ee in clone () from /lib/tls/i686/cmov/libc.so.6 #1 0xb7e04a25 in _XGetXCBBuffer (dpy=0x8ec27b0) at ../../src/xcb_lock.c:101 xcb_req = 57886 dummy_request = {reqType = 0 '\0', data = 0 '\0', length = 0} __PRETTY_FUNCTION__ = "_XGetXCBBuffer" #2 0xb7e05e83 in _XSend (dpy=0x8ec27b0, data=0x0, size=0) at ../../src/xcb_io.c:239 c = (xcb_connection_t *) 0x8ec2fc0 __PRETTY_FUNCTION__ = "_XSend" #3 0xb7e06042 in _XFlush (dpy=0x8ec27b0) at ../../src/xcb_io.c:258 No locals. #4 0xb7dde041 in XFlush (dpy=0x8ec27b0) at ../../src/Flush.c:41 No locals. #5 0x080ec3ac in CXWindowsEventQueueBuffer::flush (this=0x8ed7820) at CXWindowsEventQueueBuffer.cpp:249 No locals. #6 0x080ec4e3 in CXWindowsEventQueueBuffer::addEvent (this=0x8ed7820, dataID=11) at CXWindowsEventQueueBuffer.cpp:210 xevent = {type = 33, xany = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500}, xkey = { type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, root = 485, subwindow = 32, time = 11, x = 0, y = 0, x_root = 0, y_root = 0, state = 0, keycode = 0, same_screen = 0}, xbutton = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, root = 485, subwindow = 32, time = 11, x = 0, y = 0, x_root = 0, y_root = 0, state = 0, button = 0, same_screen = 0}, xmotion = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, root = 485, subwindow = 32, time = 11, x = 0, y = 0, x_root = 0, y_root = 0, state = 0, is_hint = 0 '\0', same_screen = 0}, xcrossing = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, root = 485, subwindow = 32, time = 11, x = 0, y = 0, x_root = 0, y_root = 0, mode = 0, detail = 0, same_screen = 0, focus = -1076737432, state = 149815280}, xfocus = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, mode = 485, detail = 32}, xexpose = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, x = 485, y = 32, width = 11, height = 0, count = 0}, xgraphicsexpose = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, drawable = 48234500, x = 485, y = 32, width = 11, height = 0, count = 0, major_code = 0, minor_code = 0}, xnoexpose = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, drawable = 48234500, major_code = 485, minor_code = 32}, xvisibility = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, state = 485}, xcreatewindow = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, parent = 48234500, window = 485, x = 32, y = 11, width = 0, height = 0, border_width = 0, override_redirect = 0}, xdestroywindow = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, event = 48234500, window = 485}, xunmap = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, event = 48234500, window = 485, from_configure = 32}, xmap = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, event = 48234500, window = 485, override_redirect = 32}, xmaprequest = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, parent = 48234500, window = 485}, xreparent = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, event = 48234500, window = 485, parent = 32, x = 11, y = 0, override_redirect = 0}, xconfigure = { type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, event = 48234500, window = 485, x = 32, y = 11, width = 0, height = 0, border_width = 0, above = 0, override_redirect = 0}, xgravity = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, event = 48234500, window = 485, x = 32, y = 11}, xresizerequest = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, width = 485, height = 32}, xconfigurerequest = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, parent = 48234500, window = 485, x = 32, y = 11, width = 0, height = 0, border_width = 0, above = 0, detail = 0, value_mask = 0}, xcirculate = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, event = 48234500, window = 485, ---Type to continue, or q to quit--- place = 32}, xcirculaterequest = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, parent = 48234500, window = 485, place = 32}, xproperty = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, atom = 485, time = 32, state = 11}, xselectionclear = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, selection = 485, time = 32}, xselectionrequest = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, owner = 48234500, requestor = 485, selection = 32, target = 11, property = 0, time = 0}, xselection = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, requestor = 48234500, selection = 485, target = 32, property = 11, time = 0}, xcolormap = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, colormap = 485, c_new = 32, state = 11}, xclient = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, message_type = 485, format = 32, data = { b = "\v", '\0' , s = {11, 0, 0, 0, 0, 0, 0, 0, 0, 0}, l = {11, 0, 0, 0, 0}}}, xmapping = {type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, request = 485, first_keycode = 32, count = 11}, xerror = {type = 33, display = 0xb72e80a4, resourceid = 3218229888, serial = 32007, error_code = 4 '\004', request_code = 0 '\0', minor_code = 224 '�'}, xkeymap = { type = 33, serial = 3073278116, send_event = -1076737408, display = 0x7d07, window = 48234500, key_vector = "�\001\000\000 \000\000\000\v", '\0' }, pad = {33, -1221689180, -1076737408, 32007, 48234500, 485, 32, 11, 0, 0, 0, 0, 0, 0, 0, -1076737432, 149815280, -1076737412, -1076737476, -1221689144, 135391056, -1076737436, -1221689148, -1221689144}} lock = {m_mutex = 0x8ed7824} #7 0x0811f124 in CEventQueue::addEvent (this=0xbfd24a3c, event=@0xb72e8140) at CEventQueue.cpp:221 lock = {m_mutex = 0x8ec23e0} eventID = 11 #8 0x081180be in CTCPSocket::sendEvent (this=0x8ed8030, type=19) at CTCPSocket.cpp:358 No locals. #9 0x08118512 in CTCPSocket::serviceConnected (this=0x8ed8030, job=0xb69118a8, read=false, write=true, error=false) at CTCPSocket.cpp:465 n = 21 buffer = (const void *) 0xb6901520 lock = {m_mutex = 0x8ed8038} needNewJob = false #10 0x0811a785 in TSocketMultiplexerMethodJob::run (this=0xb69118a8, read=false, write=true, error=false) at TSocketMultiplexerMethodJob.h:79 No locals. #11 0x08112d09 in CSocketMultiplexer::serviceThread (this=0xbfd24adc) at CSocketMultiplexer.cpp:228 revents = 2 read = false write = true job = (ISocketMultiplexerJob *) 0xb69118a8 error = false newJob = (ISocketMultiplexerJob *) 0x8ed8128 i = 0 cursor = {_M_node = 0x8eeba88} jobCursor = {_M_node = 0x8ed7a70} status = 1 pfds = { >> = { _M_impl = {> = {<__gnu_cxx::new_allocator> = {}, }, _M_start = 0x8ed7d50, _M_finish = 0x8ed7d58, _M_end_of_storage = 0x8ed7d58}}, } pfd = {m_socket = 0x8ed7d70, m_events = 3, m_revents = 46894} #12 0x081146c3 in TMethodJob::run (this=0x8ec2090) at ../../lib/base/TMethodJob.h:63 No locals. ---Type to continue, or q to quit--- #13 0x0811d908 in CThread::threadFunc (vjob=0x8ec2090) at CThread.cpp:152 id = 2 job = (IJob *) 0x8ec2090 result = (void *) 0x0 #14 0x08132845 in CArchMultithreadPosix::doThreadFunc (this=0x8ec0008, thread=0x8ec20c8) at CArchMultithreadPosix.cpp:720 result = (void *) 0x0 #15 0x081329ad in CArchMultithreadPosix::threadFunc (vrep=0x8ec20c8) at CArchMultithreadPosix.cpp:701 thread = (CArchThreadImpl *) 0x8ec20c8 #16 0xb7c8950f in start_thread () from /lib/tls/i686/cmov/libpthread.so.0 No symbol table info available. #17 0xb7c067ee in clone () from /lib/tls/i686/cmov/libc.so.6 No symbol table info available.