Ubuntu
xserver-xorg-video-ati package

  1. Bug #227520
  2. Comment #9

Comment 9 for bug 227520

Revision history for this message
Matt Cargo (mcargo) wrote : Re: External monitor resolution can't be changed on laptop (ati driver)

Sorry, to add xdpyinfo gives

default screen number: 0
number of screens: 1

screen #0:
  dimensions: 2560x1200 pixels (678x318 millimeters)

which is indeed what's happening: each screen can pan vertically. 2560=1280 times 2, but where does the 1200 come from?