Hi Karl! My name is ***** ***** I am an independent computer professional who has been paired with you via JustAnswer.com.
The Samsung SyncMaster 305T should not require any drivers to enable 2560x1600 resolution. In order to display at the higher resolution, you would only need: 1) a video card which can handle DisplayPort MultiMode, and 2) a dual-link DVI cable. Since all was working fine under Windows 7 (x86), I'd have to assume there are no issues there!
I would guess, then, that the problem is actually with the drivers for the video card (I checked to be sure, and this video card DOES handle DP MultiMode just fine, with proper driver support). Would you please try this driver for your video card to see if it makes a difference?:
Our work here is a collaborative effort, so please let me know what happens and we'll keep working till you're satisfied!
Hi Karl: I'm just checking back in to see if my previous suggestion to reinstall your video card drivers helped to resolve this issue, or whether you were still having problems achieving full resolution on your SyncMaster 305T? Please let me know.
Hi again Karl! I know you've been busy, but wondered if you'd had the chance to reinstall the Nvidia drivers and see if that helped with your monitor resolution issue at all?