I recently got a new motherboard/CPU so I did a fresh install of Kubuntu 12.10 (i386). I had graphic problems since I started using the live USB (before installing). Then, the system got constant freezes. After the installation was complete and I installed all the updates and additional applications, the problem remained: the system was constantly freezing, to the point I had to reboot several times. The image on the screen would go blank, or it would just go crazy, I kept getting error messages reporting crashes. I thought this might be a Plasma-KDE thing, so I removed Kubuntu and did a fresh install of Ubuntu 12.10 (i386). The problems were still there: I had to wipe out Unity, since compiz was driving me crazy with all the crashes. I installed Gnome classic instead and had to login with "no effects", because if I logged in with the classic session, the menus went totally bonkers (missing letters, freezes, etc). I enabled backports and pre-realeses, got new kernel and (apparently) X driver and now it's a bit better, but crashes are still there every 30 seconds, and freezes are there, as well, although not that often. I also added Intel graphics drivers repository.
I know it's not a hardware problem because I kept a Windows 7 (64-bit) partition, and I've been forced to use it these days. It works perfectly (after installing all the drivers).
I don't have the classic graphics problem of wrong resolution, but everything else is there
Motherboard: ASUS P8H61-M LX CPU Intel core i5-2500 @ 3.30GHz RAM 4 Gb DDR3 HDD 350 GB
What can I do?