Comment 2 for bug 683686

Launching compiz from a terminal from within the Ubuntu Classic Desktop session resulted in:
Checking if settings need to be migrated ...no
Checking if internal files need to be migrated ...no
Backend : ini
Integration : true
Profile : default
Adding plugins
Initializing core options...done
Initializing bailer options...done
Initializing detection options...done
Initializing composite options...done
Initializing opengl options...done
compiz (core) - Warn: Plugin 'composite' already active
compiz (core) - Warn: Plugin 'opengl' already active
Initializing decor options...done
Initializing gnomecompat options...done
compiz (core) - Warn: Plugin 'compiztoolbox' already active
Initializing move options...done
Initializing scale options...done
Initializing resize options...done
Initializing place options...done
compiz (core) - Error: Plugin 'mousepoll' not loaded.

compiz (core) - Error: InitPlugin 'wall' failed
compiz (core) - Error: Couldn't activate plugin 'wall'
Initializing expo options...done
Initializing vpswitch options...done
Initializing mousepoll options...done
Initializing ezoom options...done
Initializing staticswitcher options...done

Then looking in /var/log/kern.log I saw:
Dec 1 08:29:39 localhost kernel: [ 4224.757412] compiz[11069]: segfault at 200000001 ip 0000000200000001 sp 00007fffcd8df238 error 14 in libstaticswitcher.so[7f97e670c000+1f000]