All themes have a yellow explorer background

Hi everyone.
I've patched the necessary theme files using Universal Theme Patcher. The themes used to display fine, up until recently when (almost) every theme now gets applied with a yellow explorer background, even the default ones. I haven't edited any themes. I also tried applying them with TuneUp Styler with no luck.
The only themes that do not have this problem are the ones, I think, with images or gradients for the background, eg this one here Glass Onion Noon Theme by ~sasomkd on deviantART and the high contrast themes. The default basic theme gives me this problem too.
I tried restoring and patching again with no success.
Any help would be appreciated.

Bongo said:

Welcome to the Seven Forums
Can you post a link to some of the themes that turn yellow, was any of the themes you downloaded supposed to be yellow there?

Try Option 2 in this tutorial SFC /SCANNOW Command - System File Checker it will not harm any of your personal data or programs it will however fix any system files that have been corrupt or changed you will need to use that universal theme patcher again afterwards.
Jerry

Thanks man, sfc /scannow fixed it! Can't help but wonder what was causing the problem though- I only had a couple of files modified- explorer & explorerframe.