Built-in 2nd Monitor Port Not Working with USB to DVI External Video Cards

[markjerde]

I bought 4 ea. "USB to DVI External Video Card, High Resolution, 1600 x 1200" and they are working fine.  People are impressed by a 5-monitor laptop.  ;-)

However, the built-in additional monitor port is no longer working, even when the "USB to DVI External Video Cards" are disconnected.  This is a bummer because I use that port for a 1920x1200 display.  In "Display Properties | Settings" I can select the monitor, check "Extend my Windows desktop onto this monitor", and click "Apply", but the monitor always stays dark.  Another strange thing is when the monitor is selected and I drag it on the monitor arrangement panel, when I release the mouse button the monitor always snaps back to the previous position.

Computer Information:

Dell M90 laptop, 2.00 GHz Intel T2500 CPU, 2.00 GB of 998 MHz RAM.
WinXP Pro SP2, all software & hardware patches applied.
Built-in VGA:  NVIDIA Quadro FX 1500M
   Driver Provider:  NVIDIA
   Driver Date:        3-21-2006
   Driver Version:   8.4.2.9

Device Manager has this information for the "DisplayLink Graphics Adapter" entries:
   Driver Provider:  DisplayLink Corp.
   Driver Date:        3-8-2007
   Driver Version:   6.12.10.7

There are no errors displayed in "Device Manager".

Thanks for your assistance getting my 1920x1200 monitor working!  I *need* my pixels!  ;-)

[markjerde]

Never mind, it's working now.  I have no idea what the problem was a few days ago.