>I am using Firefox version 21.0.
>
>I did not mean a right frame by itself but the right side of the tree view (message map) frame and the message content pane.
>
>If it's a cache file issue, and not being accusatory about this at all, that is an issue for you. Not us. Many of us will wave our arms if you ask for volunteers to help test a solution, I'm sure. It's just that users should not be expected to do low level techie functions like clearing the browser cache.

Yes, and this is because some browsers have known bugs in regards to that.

For you, is still issue resolved now or you are still seeing the wrong background?