I recently upgraded from 14 to 15. The main reason why I finally had to was because on fedora 14 after a usual package upgrade a couple of days ago my windows contents turned white if the window was big enough. Both vertical and horizontal size were affected. Usually if I resized the window to a small enough size the content would appear, but there were some natively small windows/popups that can't be resized that were white and there was nothing I could do about them. Everything seemed to work though, if I could guess the contents of the window and click in the right place.
After the upgrade to fedora 15 similar thing happens, only the window content turns black when resized to a big enough size. It's not the same for all applications, for example when I maximize Firefox it turns black, but I can maximize Thunderbird and it works es expected.
After the upgrade I had some broken packages related to nvidia kmod for f14, but I removed them and the bug still appears.
Gnome shell seems to working fine, I also have some gnome shell extensions installed.
What could be causing this? What can I do to test or fix it? Do you think that a clean install of fedora 15 might help?