Nouveau driver glitch on Ubuntu 13.04 for GeForce 6150SE

Hi,

This only happens to Ubuntu 13.04, as my GeForce 6150SE card was working fine for Ubuntu 12.10. The Nouveau driver glitch will cause my whole system to freeze under certain conditions.

I first get my system freeze when starting virtualbox, which is installed from the offical Oracle virtualbox PPA. Duplicated several times -- Freshly boot into X, then start virtualbox from within xterm via "virtualbox &", 2 seconds later my whole system freeze up.

Google search indicated that it might be cause by the offical Oracle virtualbox PPA, so I followed the advice to switch to the offical Ubuntu virtualbox from the software center, but get into system freeze doing exactly the same thing. Duplicated several times as well.

I was about to conclude that it is the virtualbox's problem when I suddenly remember that I've got into such system freeze before doing something entirely different, because the symptom is exactly the same. So I tried again -- "startx -- :1" to get me into another X session, and quit.

Yes, then and there, I get into such system freeze again. The symptom is that the display turned black, then a random pattern tiled across the whole screen.

Comparing with the previous Xorg.1.log, the lines that didn't get output are:

 (II) NOUVEAU(0): EDID vendor "ACR", prod id 426
 (II) NOUVEAU(0): Using EDID range info for horizontal sync
 (II) NOUVEAU(0): Using EDID range info for vertical refresh
 (II) NOUVEAU(0): Printing DDC gathered Modelines:
 . . .

The whole unloading part (filtered by "sed 's/\[[^]]*]//'") of my previous Xorg.1.log is at http://paste.debian.net/5260/, the whole un-filtered file is at http://paste.debian.net/5261/.

Here is my GeForce 6150SE card:

$ lspci | grep VGA
00:0d.0 VGA compatible controller: NVIDIA Corporation C61 [GeForce 6150SE nForce 430] (rev a2)

I guess I'll turn it into a bug report.
Any other info necessary?

Thanks