[Split off from bug 13317] Table cells with visibility:hidden paint their table section and row backgrounds. See that attached test case.
Created attachment 14057 [details] Test case Opera, Safari 2 and WinIE render nine green squares. Firefox gives radically different results.
Created attachment 14058 [details] Avoid painting any backgrounds behind invisible cells
Comment on attachment 14058 [details] Avoid painting any backgrounds behind invisible cells r=me
Landed in r20931.