When did it start doing this? Did you change anything? Have you tried any other distros?
The fact that it does it with a regular installation, a LiveCD, and during a new installation, yet rescatux works fine, tells me that there is some incompatibility with Ubuntu 12.04 and your hardware. But if that's the case, I'm not sure how you ever got it installed in the first place.
Last edited by suicidaleggroll; 04-01-2013 at 02:11 PM.