Issues with ATI MV2260 video card on Precision T3500

I have several Dell Precision T3500's that came with ATI MV2260 video cards.  In the past couple of weeks, I have had issues now with three of them.  Each have dual monitors with display port to DVI adapters connected to DVI cables to the monitors.  What happens is one monitor will stop showing a display.  (Keep in mind, dual monitors have been working perfectly from day 1 of purchasing these computers with just the default Dell build). You can swap the monitor cabling around and confirm that it isn't a bad monitor.  No matter what combination of cabling, updated drivers, etc., only one monitor will display at a time with DVI adapters. However, if I connect a display port to VGA adapter, then the 2nd monitor will work when connected using VGA.  This happened on two computers.  Now I have a third that I'm working on reinstalling the OS.  When connected using display port/DVI, you can't even get it to show the BIOS on either port of the video card.  I have to use a display port/VGA adapter to get to the BIOS.  Then, strangely, when connected to VGA, once it gets past the BIOS screen, after selecting the DVD drive to boot the Windows installer disc, the screen goes black for several minutes while it is booting Windows from the disc and then eventually it displays the Windows setup screen after it's completely booted.  I believe that same behavior was occurring whether connected VGA or DVI on each computer, where it doesn't display the Windows boot process and then magically reappears when Windows is booted.

I've troubleshooted a lot of video cards, drivers, dual monitors, adapters, and cables in my time, but this is really strange.  I'm about to just purchase new nVidia cards.