I see a compiz freeze (compiz cpu goes to 100%) whenever I log in using the "ubuntu" (i.e., unity 3D) window manager selection, and open a file with an editor. I usually do this using vi in an xterm window, but I've checked out gedit with the same result. I think it would be interesting to use unity 3D, so I'd like to find a solution.
This is the sort of compiz freeze/hang where the mouse can be moved, but nothing can be selected, and the (kernel) is still reading keyboard keypresses.
I am using a lemur ultra (lemu4). Since some people are using unity 3D with no problem, I have to believe it is something particular about my installation or my hardware. I reinstalled ubuntu 12.04.1, and did only a small amount of reconfiguration before testing for the freeze -- which it promptly did. The changes I made (using ubuntu 2D) before testing were
1) I allowed system updates to get started
2) I swapped the ctl and caps-lock keys (for my habits)
3) I restored my home directory from before the reinstall -- tailoring shell functions
and setting command line editing via vi keys.
4) I added another user name to the system
5) I re-established /etc/hosts for convenience on the local network
6) I logged out and selected unity 3D ("ubuntu")
7) vi was still working, but unity 3D cube rotation features were not yet active -- I installed
compizconfig-settings-manager, and enabled Viewport Switcher, and finally ran "compiz --replace" to finally enable the 3D cube rotation.
I then opened a file with vi in a terminal window, and compiz immediately hung.
I believe one problem must be in compiz (which hangs), but there may be an underlying problem due to the graphics support on the lemu4 (since not everyone is having this problem). I haven't figured out which driver that is, though I think it is from Intel; I would be happy to do some testing, but haven't managed to build compiz yet, let alone the possibly suspect graphics support. Any suggestions to get this working will be appreciated.
I can recover from the freeze by using ctl-alt-F1 to get to tty1, where I can kill the hung compiz (kill -9 pid) and restart using a service request to lightdm. That is less than satisfactory, particularly if I ever want to write to a disk file