Re: IGP 8300 freezes with 177 and 180 on ubuntu
Is this bug report from after a freeze, before you shut down the system? If not, please get one of those, which you should be able to do over SSH.
When the display is frozen, can you attach to the X server with GDB and get a backtrace? "gdb /usr/bin/Xorg `pidof X`" should attach and then just run the "backtrace" command and paste the output here. Also, there are some messages in your system log from the vboxdrv driver doing some slightly shady things with interrupts. Does the hang still occur if you disable VirtualBox?