Here a possible explanation about what is going on:
original link Here's a better dmesg, however instead of being CTRC 5 and 6; they are 9 and 10 (and so the error is "*ERROR* failed to set mode on [CRTC:10]"). CRTC:9 is the VGA output, and CRTC:10 is the TV output. However, this card (an NV4E - GeForce 6150 LE - integrated onto the motherboard) HAS no TV output (or a DVI output either, which is also detected). So CRTC:10 is connected to a phantom output. Curiously enough, the framebuffer has a physical resolution of CRTC:9 (the VGA), but a virtual resolution of CRTC:10 (the phantom TV output) - so it only fills part of the screen.
Here another thread here in the LQ with about same problem:
And here some possible solution or at least some lights on the matter:
Originally Posted by pandanuma
...no key combo will unfreeze it...
I don't think the computer is totally froze, have you tried ctrl+alt+(F1-F6)
? It will drop you to the virtual consoles.
From there you can kill the frozen processes and restart the login manager and GUI.
I would turn off the screensaver/power saving to avoid this issue, so you can manage the problem without having things freezing.
Which video driver is currently loading? nouveau ? And which kernel is running there? Seen like nouveau is the problem here.