I'm having the exact problem described by Nico in comment #32 if I try to switch users with compiz enabled in gutsy.
If I disable Sync to VBlank - i get the white screen issue described above (about 90% opaque) and typing my password gets rid of it.
If i disable compiz altogether - no problems.
This is all in the latest gutsy, with all updates.
I'm having the exact problem described by Nico in comment #32 if I try to switch users with compiz enabled in gutsy.
If I disable Sync to VBlank - i get the white screen issue described above (about 90% opaque) and typing my password gets rid of it.
If i disable compiz altogether - no problems.
This is all in the latest gutsy, with all updates.
Btw, is this the same bug as #135809 ?