Comment 173 for bug 127101

Conn, could you post an Xorg.0.log file from your machine?

For extra information, can you enable the following option in the Xorg config file's "device" section for the video card:

 Option "ModeDebug" "true"

I'd suggest opening a separate launchpad bug, as the symptom is different. Let me know what that bug is (here, by email, or subscribe me)!

It might be related to the problem Claudio is seeing, I think you both have the same card, and it appears there are a couple of other 855 specific bugs out there.

If you have access to a second machine, could you try pinging / ssh into your machine which freezes, as I've heard of at least one other case where after a VT switch, someones machine would appear to freeze, but still be accessible via the network. (In this bug, the machine really does lockup solid).