This was due to Firefox not using _NET_WM_SYNC_REQUEST to let compiz know when it was done drawing so it could wait to draw it until it was ready. Firefox 3.5 corrects this problem so you should not see this anymore when using that version.
This was due to Firefox not using _NET_WM_ SYNC_REQUEST to let compiz know when it was done drawing so it could wait to draw it until it was ready. Firefox 3.5 corrects this problem so you should not see this anymore when using that version.