Laptop doesn't recognize max resolution on external LCD

[flashbacck]

Hi,
I'm having trouble getting my laptop (dell 640M w/ Intel 945gm express chipset) to recognize the correct maximum resolution of an external LCD (Acer AL2216W) that's connected to it via VGA. I know the laptop should be able to output higher resolutions, just prior to connecting the AL2215W, I had it outputting 1280x1024 to a 19" 4:3 LCD. However, the only options I am given with the acer monitor are 800x600 and 1024x768.

Various stuff I've tried:
*Tried downloading newest intel driver (wouldn't install because it's not validated by Dell), but I have the latest dell driver for the chipset.

*Updated bios to latest from dell

*downloaded INF file for the AL2216W and tried installing that and manually selecting it as the driver for the monitor.

*various combinations of unplugging and replugging and rebooting.

I've found a handful of posts via google of people having the same problem, however no one has posted any solution.

Any suggestions appreciated. Thanks!

 

[cusideabelincoln]

Only thing I can think of is unchecking the box under the advanced display properties to "hide modes this monitor does not support".

 

[flashbacck]

I dunno what happened. I uninstalled the Intel Graphics Media Accelerator driver from the add/remove programs, and after a reboot it was automagically working 😵

 

[flashbacck]

well that didn't last long. I unplugged my laptop from work so I could use it at home. When I brought it back, and plugged in the monitor, the max resolution was back at 1024x768.