My FIFA 10 doesn't start, so I tried to "clean fat", it gave me some errors but I continued, it analyzed zdata_01-04, but it stops at zdata_05.big, just won't move on. Whats the problem, help?!

If the zdata big files get too large it can cause the game to malfunction. Try replacing your zdata_05.big file with the original from the game CD and see if it now works (of course you would lose all the edits that are contained in your amended zdata_05,big file)