Display Resolution Issue

A couple of days ago my RAID array failed and I ended up having to install Windows from scratch. Everything is pretty much working properly, except for one issue with my display that I can't seem to repentantly correct. When the computer first boots up into windows, there is a streak (for lack of a better word) going across the screen horizontally, about 1/3 up from the bottom, only a few pixels wide. It slightly distorts anything near it, text, windows, etc. The desktop also appears to be slightly distorted in its placement as well, the taskbar looks like it's slightly below the bottom of the screen, etc.

I have been able to correct the problem by changing the desktop resolution, and then changing it back, but the problem re asserts itself after a reboot.

I am running a nVidia GeForce 9800 GT at 1920x1200 under Windows Vista x64 using the very latest drivers attached to a 24" Sceptre LCD Widescreen monitor connected via DVI. If it makes a difference, I also have an HDTV connected via a DVI to HDMI cable running at 1080P (1920x1080).

Any thoughts would be appreciated, and I can likely provide screenshots if that will help.

I'm pretty sure the video card is fine. I actually just replaced it because of a previous one that had overheated. I can play games at max settings without any graphical anomalies or performance issues, and the card isn't running hot.

Also, the problem didn't happen in Vista x86 with older drivers.