Dual monitor flicker on Windows 7 - previously worked on Windows XP

Question

I have a dual monitor setup as follows:

• Radeon HD2600 XT video card (MSI RX2600XT-T2D512EZ/D3)
• Monitor 1: Samsung Syncmaster 2032BW (1680 x 1050)
• Monitor 2: an older HP L1720 (1280 x 1024)

Both monitors are connected via DVI. Previously I was running Windows XP (Pro) with Ati Catalyst 8.5 without problems. But after installing Windows 7 (Ultimate) and the latest Catalyst Display Driver for Win7 32-bit (v 12.1), I get flickering on the second monitor.

I read many similar reports involving Ati Catalyst, but the solutions I've read about aren't working:

• It doesn't seem to be a hardware problem; on exactly the same hardware setup Win7 has problems whereas XP didn't
• I'm using the latest display driver
• I've tried changing the refresh rate. For Monitor 1, 1680x1050 resolution is recommended and 60 Hz refresh rate is enforced. For Monitor 2 1280x1024 is the recommended (and maximum) resolution. There I can choose between 60 and 75 Hz, but when I set it to 60 Hz, after about 30 seconds the monitor blanks and switches back to 75 Hz. Also during the time it's set to 60 Hz the flickering isn't resolved, though there seems to be somewhat less)
• I've tried disabling AMD Overdrive (this seems to work for many people, but it doesn't solve my problem)

What else can I try to solve this problem in Windows 7?

Answer 1

OK, I've finally managed to get rid of the problem (so I guess I'll answer my own question). One more try that did not work:

• Uninstalling Ati Catalyst completely did not solve the problem.

The solution: I installed an earlier version of Ati Catalyst (version 10.5), and after a reboot the flicker was gone (I don't know at which version number the problem was introduced, I'll just keep using this version for now).

With this version I am also able to keep a 60 Hz refresh rate on the second monitor (I get the dialog with "Do you want to keep these settings?", which did not appear with the latest V12.1 driver). Although the refresh rate itself was not the cause of the flickering.