I opened a Windows 7 virtual machine tonight from VirtualBox, and compiz crashed, resulting in me thinking for about a minute that my laptop had frozen, but it came back with a compiz crash after it restarted and offered me to file a bug report. It was fine when it came back.
Apparently, I can't file a bug report because precise is out of beta. Should I panic?
You can reconfigure Apport to report bugs from crashes. If you're willing to submit a good bug report, that may shed light on the problem and/or get it fixed.
Compiz is your window manager. When it crashes, you don't generally lose data from any applications. So no, you needn't worry.
If you want, you can switch to Unity 2D (select Ubuntu 2D instead of Ubuntu at the login screen, by expanding the session type drop-down menu, which looks like a circle with the Ubuntu icon in it). Unity 2D uses Metacity rather than Compiz, so that will make this crash go away.
