@ kl522

I've seen the 'lost window decorations' thing on occasion.

As time goes by I have retired a few of the Compiz effects,
such as SCALE and EXPO. I think this MAY have reduced the
frequency of these occurences, but that's only a guess.

I'll give your recovery technique a try the next time I
see the frames and such corrupted. Up 'til now I've just
used Control-Alt-Backspace after closing things down,
if or when that's possible.

There is a Compiz re-start menu choice; have you tried that
to correct the 'decorations' problem?