I haven't had any success with this problem.
I am running a mid 2010 MacBook Pro 2.53 GHZ i5 with 5 Gb of RAM, using Lion with all patches up to date.
I am having a problem where my video freezes, and when I move my mouse around the cursor sort of "scrubs" the screen clean in big squares, eventually revealing the log on button below, which then works.
I have called Applecare, who had me install patches and tweak screen saver settings, and none of it has made this go away.
Does anyone else know about this? I'd be eternally grateful.
thanks
michael

Are you using the integrated graphics or the dedicated graphics when this happens?

It doesn't seem to matter. I have turned auto switching on and off and have had it on battery and on AC..it seems to happen independent of that.
I thought of that...apparently that's not the problem.
thanks though....

Have you tried any pmu or similar resets?

no, and I don't know what PMU is.

Maybe on these machines it's called NVRAM. If you look on apples site for startup key combos I think it's option command p r.

Is it like this?

PozjWKFbXjY

If so, my previous MBP did this. Several folks on the Apple Discussion Forums had logic boards replaced and the issue persisted. Some folks point to Flash being the culprit. I never did solve it. I ended up wiping the machine and selling it because work provided me with a MBP. No word from the buyer about the issue, though I did warn them.

no, that's not the problem.
The screen appears to freeze. If you move your mouse over it, it wipes away in big squares where the cursor goes, and reveals the login window underneath. This then works.
Its weird.

no, that's not the problem.
The screen appears to freeze. If you move your mouse over it, it wipes away in big squares where the cursor goes, and reveals the login window underneath. This then works.
Its weird.

I actually have had something like this happen to me, with the exception that my computer didn't quite freeze. After an hour of inactivity I would have to wipe away the screen with the mouse cursor to get to my Login screen. It was as though my screen had been turned into a giant "scratch & save" ticket. I had my computer Security & Privacy set to "Require password [1 hour] after sleep or screen saver begins" and "Logout after [60] minutes of inactivity". I always assumed it was a bug as I was an early adopter of Lion but it still happened after each update. I also tried re-installing Lion and that didn't make a difference. Finally, I disabled "Require password [1 hour] after sleep or screen saver begins" and it hasn't happened since.

That's precisely the problem I have! AppleCare had me make that change and it didn't seem to help, although it is seemingly absent now.
Weird.
It really seems like the kind of thing one would expect from a virus--computer behaviour designed to be annoying and bizarre.
thanks...
m