Hi, as always, apologies if this has been posted before. I've noticed over the last few days that FS9 FPS has dropped dramatically. The problem in particular seems to happen whenever I add weather to the environment (I use REX). I get 29 fps with clouds at Seattle in the default Cessna, and around 25 with even FS9's own weather engine providing the weather... It all used to run just grand: I have it set at 41, to get 40 fps, the way I like it, and I've tried the usual tricks (deleting FS9.cfg and re-installing FS9) but the problem refuses to go away. My last desperate act is to go back to another driver version (I run Catalyst 10.7, I'm sure with 10.6 I had better results). I have the software, I'm just not sure how to go about un-installing it all. Can someone point me in the right direction, and is a tool I found called 'Driver Sweeper' a necessity for this task? I run Windows 7 x64, have ATI 5770's (in Crossfire, which for some reason gives me better FPS) and an i7-860. I fly FS9.1. REX puts the clouds in my sky, IFSD Irish Scenery gives me somewhere to fly to and FSNav to tell me how to get there (or, to be more precise, where I actually am - the two are not always related) Cheers.s/

Nevermind, figured it out myself. 1. downloaded another copy of the latest driver (10.7)2. ran the installer, which gives you an option to un-install. un-installed3. reboot in safe mode, ran Driver Sweeper. There where quite a few files left behind. removed them all4. reboot5. ran 10.6 installer, rebooted. So far initial results look promising. From the AMD forum it seems quite a few people are having trouble with 10.7. A lesson to be learned then: don't just update because it's there, take a look around first to see if others report problems. Give it a month or so and then think about upgrading.