gnome fails to start - segfault in migrate-trash.c

Binary package hint: gnome-session

after todays updates on logging it gnome i get the following error

"Your session only lasted less than 10 seconds. If you have not logged out yourself, this could mean that there is some installation problem or that you may be out of disk space. Try logging in with one of the failsafe sessions to see if you can fix this problem."

xsession errors:

/etc/gdm/Xsession: Beginning session setup...
Setting IM through im-switch for locale=en_GB.
Start IM through /etc/X11/xinit/xinput.d/all_ALL linked to /etc/X11/xinit/xinput.d/default.
SESSION_MANAGER=local/titania:/tmp/.ICE-unix/6233
CRTC 4a Timestamp: 1668314
CRTC 4b Timestamp: 1668314
Output 4c Timestamp: 1668314
Output 4d Timestamp: 1668314
Output 4e Timestamp: 1668314
Reading config file /home/sam/.gnome2/monitors-onetime.xml
CRTC 4a Timestamp: 1668314
CRTC 4b Timestamp: 1668314
Output 4c Timestamp: 1668314
Output 4d Timestamp: 1668314
Output 4e Timestamp: 1668314
expected keysym, got XF86KbdLightOnOff: line 70 of pc
last scanned symbol is: XF86KbdLightOnOff
expected keysym, got XF86KbdBrightnessDown: line 71 of pc
last scanned symbol is: XF86KbdBrightnessDown
expected keysym, got XF86KbdBrightnessUp: line 72 of pc
last scanned symbol is: XF86KbdBrightnessUp
Warning: Type "PC_RALT_LEVEL2" has 2 levels, but <LALT> has 3 symbols
                  Ignoring extra symbols
Warning: No symbols defined for <SYRQ> (keycode 92)
Warning: No symbols defined for <II65> (keycode 101)
(there are hundreds of these, i can post them all if you want. i have seen them before so i dont think they are the problem - sam)
Warning: No symbols defined for <I7E> (keycode 254)
Warning: No symbols defined for <I7F> (keycode 255)
Shutdown failed or nothing to shut down.
xrdb: "*Label.background" on line 220 overrides entry on line 150
xrdb: "*Text.background" on line 226 overrides entry on line 191
xrdb: "*Label.foreground" on line 232 overrides entry on line 151
xrdb: "*Text.foreground" on line 238 overrides entry on line 192
Window manager warning: "" found in configuration database is not a valid value for keybinding "toggle_shaded"
Window manager warning: Failed to read saved session file /home/sam/.metacity/sessions/default0.ms: Failed to open file '/home/sam/.metacity/sessions/default0.ms': No such file or directory
(gnome-panel:6356): GnomeUI-WARNING **: While connecting to session manager:
IO error occured opening connection.
(nautilus:6357): GnomeUI-WARNING **: While connecting to session manager:
IO error occured opening connection.

however the panel and nautilus are started, so i can use the desktop. if it click ok in the dialog i get taken back to the login screen.

sometimes i dont get the message and get taken straight back to the login screen.

my gnome-session version is 2.22.1-0ubuntu3

the first time this happened i got an oops in dmesg, see Bug #214563 (is it possible for an application bug to cause and oops?)