Hi, johnmd

Thanks for your comments.

It sounds like your problem is a bit more dangerous than my own.
I don't seem to be in jeopardy of losing any LO material,
just more of a nuisance doing the Ctl-Alt-Backspace thing.

I can live with this problem, but I'd like to understand it better
and localize it a bit more.
I am spending a little time now with Mint 11 LXDE to see if that distro
behaves any better.

My problem occurs so rarely, it's will be hard to observe any
relative differences if both have the problem.
Conversely, I'll have to work with Mint for some time before I
would hazard saying it doesn't have the same difficulty as Knoppix.

Mint 11 LXDE is a very nice alternative to Knoppix 6.7, so I don't expect
this to be an unpleasant experience.

Best regards, utu