So I've been having nightmares with 2.6.31 and tried 2.6.30 with the same problem, my wi-fi kept locking the system. 2.6.32 fixes that, but even better, it gives me open source ATI drivers and lovely 3D with no proprietary driver. Absolutely superb it is too, Compiz is flying around nicely, will test some games later but it feels very snappy. Btw it's not compatible with the proprietary ATI drivers which is why I tried the open ones. I'm glad I did now!
I've run the usual crash conditions and it coped fine so it looks good.
1. System -> Hardware Drivers -> Deactivate any ATI drivers and restart
2. Go to http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.32/
3. Download and execute the following (in this order, switch to 64 if need be)
5. Add the xorg-edgers PPA (https://launchpad.net/~xorg-edgers/+archive/ppa), update, upgrade.