Bug#529178: video-radeon: Probably hardware limitation
Followup-For: Bug #529178
This is probably a hardware limitation of the card.
AFAIK dual-link dvi is needed for modes above 1280x1024 to work reliably
over DVI. Some card - monitor combinations might work but others would
Better cards have higher-rate transmitters that can do modes slightly
larger than 1280x1024 but a 22" screen is likely over-spec for any
single link card so there is no guarantee it will work.
Dual link cards start somewhere in the X1300-X1600 range for Radeons