Ok it ran all day about 8 hrs on my desk without a Kscreensaver and No Problems at all..
I right clicked the Desktop and Locked it..
The screensaver started. About 1 min later I hit the touchpad started to enter the Password.. and Complete BlackScreen lockup with my Mouse cursor floating around..
Waited...Waited...Waited... 5 min no luck..
The only way to shut this puppy down was the Power Button..
Rebooted to Sabayon..Firefox restarted and remembered the pages...natch..
So the BUG appears to crash Kwin with Kscreensaver.
Kscreensaver has always been reliable but not with KDE 4.6 at this time..
Criticism accepted for Solutions that work. ;^)
Sabayon 13-DEBIAN 8- #! -Sid-Slackware 14-Calculate 13-Bridge