So here's the problem. When I close my lad , everything blocks, there is a black screen and frozen mouse pointer. Everything else works just perfectly, logout, screensaver... I'm running Mint Elyssa, my notebook configuration is : intel centrino 1,4ghz, 768mb of ram, intel graphics 64mb(integrated), HardDisk-20Gb (mint installed all over it, I had original Windows XP with licence, but I've erased it

).
This is a common problem on Ubuntu forums. I know that it has something to do with compiz, but I need it because, without it, windows are slow, I don't need any special effects...
PLease help, I would be very happy, if I solve this problem.