I have a Dell Latitude D600. It has a "Radeon Mobility 9000 M9 (R250 Lf)" graphics card, and an internal 1400x1050 display. I recently picked up a Chimei CMV 221A LCD monitor, capable of doing 1680x1050. The closed-source fglrx driver picks this up and does the right thing - offering both 1680x1050 and 1400x1050 resolutions. The open-source radeon/ati driver, however, loses it's tiny little mind. It refuses to accept that 1680x1050 might be a valid resolution, telling me that
(WW) RADEON(0): Mode 1680x1050 is out of range.
(WW) RADEON(0): Valid modes must be between 320x200-1400x1050
If I plug in the external monitor after X has booted, it sends 1280x1024 out to the LCD. Worse yet, if I start X with the monitor plugged in, it sets both the internal LCD and external display to 1280x1024. And the bottom of the screen isn't visible! Argh!
The fglrx driver, on the other hand, works fine. But the previous version of the closed-source driver had a boned version of libGL, and the latest version has dropped support for this graphics card. Sigh.
I will attach two xorg.confs and two Xorg.logs to this report, for the radeon driver and the fglrx driver. I can also generate one for the radeon driver booting with the external monitor plugged in, if it's useful.
This is with current Dapper, btw.