Odd behavior when switching users with KDE

[bhemenway]

I'm running KDE (3.5.5) and KDM (3.5.5-r1), and when I switch users the screen becomes garbled, it looks like when, on an old computer, you move a window faster than the screen can redraw, and you're left with a trail of windows that are all slightly offset. If you press any key, the "unlock screen" dialogue box appears, and once you log in the screen comes back to normal.

Has anyone else experienced this? I'm trying to convince my girlfriend that Linux is great and having garbage come up on the screen every time she logs in is not helping the cause.

Also, on a slightly different topic, I don't use a screensaver, but my girlfriend does, and after she logs in, even if she's completely logged out, her screensaver will come on for my account.

Any thoughts would be appreciated. Thanks.