I have a very weird problem with my 5870. Yesterday it worked fine, but it wouldn't downclock when idle even though it wasn't OC'ed.

I did a fresh install of OS and tried the 10.5 driver. I only installed the display driver, not CCC. I then got a VERY long ghosttrail if I dragged a window in circles around another open window. You know, like a really slow and old computer.

Then I installed the 10.7 display driver...same problem.

I did a new reformat and tried 10.8beta...same problem.

I have run 3D Mark Vantage with no problems but why this ghosttrail has suddenly come I have no idea. Is my card broken, you think?

No your card is not broken, I don't even think its possible for a driver to break your card. If it was working fine before with the 10.5's reinstall those after uninstalling your current driver/CCC.

It was not quite like that.

I used 10.7 with CCC and it worked fine. Problem was it wouldn't downclock when idle.

I did a reformat and installed 10.5 with no CCC...got trailing.

Installed 10.7 with no CCC...got trailing.

Did a reformat again and installed 10.8beta with CCC and trailing again.

Now I'm doing another reformat and will try to install 10.7 with CCC.

If my card isn't broken, I have NO idea what's going on. Not saying the drivers broke my card, I know that's not possible. But something must have happened.

I found a solution. Switching to an Aero desktop theme stopped the ghosting. Weird solution, but it works.

Stupid question but did you update windows fully? Could be something involving DirectX or .Net.

Nah, haven't updated .net manually, I guess Win7 does that automatically, I don't know...I believe directx got updated as I installed Bad Company 2.

It should, check to see if you've got it installed and updated just in case though.