Suggest:
1. Uninstall all video drivers.
2. Go to Driverheaven.com and use their driver cleaner to remove all remnants of ATI drivers.
3. Mount only the PCIE card and install Catalyst driver.
4. Mount other ATI cards without installing more drivers. The Catalyst should handle ALL Radeon cards.
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The above is a post I made earlier. Did you try that?
If you did and your other ATI cards didn't work with your "x series" card, then it's possible you'll have to forget ATI entirely. (ATI is not really in the multi-card, multi-monitor market... they are into gaming. It would be no surprise that they are no longer viable for trading with more than 2 monitors.)
1. Uninstall all video drivers.
2. Go to Driverheaven.com and use their driver cleaner to remove all remnants of ATI drivers.
3. Mount only the PCIE card and install Catalyst driver.
4. Mount other ATI cards without installing more drivers. The Catalyst should handle ALL Radeon cards.
_______________________________
The above is a post I made earlier. Did you try that?
If you did and your other ATI cards didn't work with your "x series" card, then it's possible you'll have to forget ATI entirely. (ATI is not really in the multi-card, multi-monitor market... they are into gaming. It would be no surprise that they are no longer viable for trading with more than 2 monitors.)