I'm having the same problem and the instructions do not apply because Compiz does not crash.
Save from the panel disappearing, it keeps running normally. In fact, it's not even that the panel disappears, it's just rendered incorrectly: sometimes I get a black bar, sometimes a bar with fake transparency and sometimes artifacts. But in all cases I can click blindly on it and confirm that the indicators and notification area are still there.
@Alex and @Seb:
I'm having the same problem and the instructions do not apply because Compiz does not crash.
Save from the panel disappearing, it keeps running normally. In fact, it's not even that the panel disappears, it's just rendered incorrectly: sometimes I get a black bar, sometimes a bar with fake transparency and sometimes artifacts. But in all cases I can click blindly on it and confirm that the indicators and notification area are still there.