ATI Radeon 4670 Display Port Problem

[bcsaji]

I have an ATI Mobility Radeon HD 4670 (on my Dell Studio XPS 1640 notebook) and I just tried to use my external monitor (Dell P2210) through a DisplayPort cable, but it did not work in Windows 7 (x64). It did display the BIOS and the Windows startup screen, but after the startup the (external) screen went black. My guess was that it could be a driver issue, thus I just tried to roll back the driver, but it did not solve the problem. I currently use Catalyst 10.3 beta (driver 8.710.3.0). Do you have any idea what could be the problem?

 

[valtonray]

display port SHOULD work, but you may want to see if you can lower the resolution.

 

[bcsaji]

display port SHOULD work, but you may want to see if you can lower the resolution.

Yes, I have tried playing with the Catalyst Control Center, e.g., decreasing the resolution, the refresh rate, etc., but nothing changed, the monitor remained black.

 

[bcsaji]

Does anybody else use ATI Radeon 4670 with external monitor via a DisplayPort cable?