Cannot extend my desktop -it recognizes the second monitor, but does nothing

[ptorres]

I'm trying to set up a dual monitor display, so that I can extend my desktop to the second monitor, but I can't get the second monitor to enable. The system is detecting it, but it won't enable.

I'm running WinXP with a ATI Radeon x300/x550/x1050 card. The two monitors are connected to the same card (one of them with a DVI/VGA adapter).
When I check the display properties, I see:
1. Default Monitor on ATI RADEON x300/x550/x1050 Series
2. (Default Monitor) on ATI RADEON x300/x550/x1050 Series - Secondary.

When I click the secondary monitor, it asks me if I want to enable. I click yes and it acts like it's enabled. I check the little "Extend my Windows desktop onto this monitor" box, click okay, the system thinks about that for a few secs and then greys out the second monitor again.
The same thing happens when I try it through the Catalyst Control Center - it sees the second monitor, allows me to right-click it and click enable, then it greys-out again. The second monitor is showing just a cloned image of the first monitor.

Anyone has some suggestions? Any help would be much appreciated.

[Jacek]

This kind of discussion have been appeared to this forum a number of times and so I would like to suggest you to refer those first and see if that helps you somehow:

how to connect dual monitor in sli config
Dell 810 laptop Dual Monitor Issue
dual monitor for Asus EN9400 GT
Windows 7 dual monitor
Dual Monitor Display

[ptorres]

Thanks for the posts! However, I took a look at them and tried different things, but nothing happened...

THe problem here is that the monitor seems to be expanded (both at Window's and Catalist's Control Panels), but do nothing. It just "blinks". I just see a mirror of the image in the second monitor...