I run Fedora (currently version 16, but this problem has been around a while) and occasionally when I switch virtual terminals (VTs) the new VT shows a corrupted version of some data that was previously displayed on the old VT. For example, if I was watching a youtube video in VT1 and press CTRL-ALT-F2 to switch to VT2, where I am logged in to a second X session, the X session doesn't show a login on a blank screen; it shows a login on a screen that appears to have a tiled corrupted version of the youtube video as wallpaper. Or maybe just gibberish.

Here is a sample. It's not clear in the photo because my phone's camera washes out the dialog box, but the unlock dialog box is properly drawn and everything works perfectly fine after unlocking the workstation.

![enter image description here](https://i.stack.imgur.com/c0q2Z.jpg)

I would like to find some way to prevent this from happening, as it's quite ugly and not to mention a security or privacy risk when two different users are sharing the same workstation and some random image isn't even on the screen anymore appears in the other session's lock screen.

In case it matters, I have a adeon HD 5800 Series video card and I'm using the stock Free AMD drivers that ship with Fedora.

How can I prevent this issue from happening, or at least force the screen to refresh on the lock screen so that this corruption doesn't stay on the screen?

I've tried playing with various screensavers and lock screen options and nothing seems to be able to prevent the corruption.