So I scavenged around for settings that might fix the problem. After a lot of restarts of the Xorg server I got the problem ironed out. The following lines have to be added to your xorg.conf file in the Device section:
Option "UseEDIDFreqs" "false" Option "ModeValidation" "DFP-0: NoMaxPClkCheck, NoEdidMaxPClkCheck, AllowNon60HzDFPModes"
UPDATE: It seems this fix is only needed if you have an "older" nvidia card like my gforce 5600. On my 8600 GT the hack is not necessary.
I bought us a Belinea o.display 2_22" wide LCD Monitor a few weeks ago to replace a 15 inch LCD. We mainly use it to watch TV using MythTV. I chose this model as I could get it below 200,- Euro, it had both VGA and DVI inputs, it had a 1600×1050 resolution and 22 inches are a nice size to watch TV.
The VGA connection worked perfectly out of the box using Xorg 7.3 from openSuse 10.3. What did not work was the DVI connection. The maximum resolution I got out was 1280 and this looks awefull on LCD. I got discouraged by the few comments that floated arround in forums. All hinted that the problem seemed to be my nvidia 5100 based card or that I would need a dual link cable to get this setup working. But, as the Monitor came with a single link cable and it seemed to work on Windows XP I concluded that it had to be the drivers of the card.