Flickering on flatscreen when in dual monitor mode

[Ucime]

I just started using a flat screen monitor attached to my laptop so I could have two monitors for my desk top.

The laptop is an HP/Compaq nc6400 and monitor is an Acer AL1917W. When I do this I get a lot of flickering on the flat screen.

I don't think there is anything wrong with the flat screen because the flickering goes away if I close laptop and just use the monitor. Also, there is no flickering on the laptop when I'm using both at same time.

The refresh rate on both is 60Mhz. That is the only value that is available for any of the screen resolutions. I didn't think that was the problem because my understanding is that with flat screens the refresh rate really doesn't matter.

I've downloaded the drivers for the Acer Monitor and installed them thinking that might help but still no luck. Any idea how I can eliminate the flickering?

Thanks in advance for any help.

Here are screen prints of the Settings tab of Display Properties.

 

[Ucime]

What I didn't notice was that there was a tab under the Advanced Settings called "Interl (R) Graphics Media Accelerator Driver for Mobile".

When I opened it there were additional options and under one of those I could change the properties of the monitor to 75 Mhz.

All is well now.