Need Help!! "Out-Of-Sync error"

[irock]

plz help i realy enjoyed playing multiy payer, and now there is a out of sync error mrssage apering when i try to join a game. i looked at another persons form and they sed to look at the resorce files. i found a set file so i deletede it like it told me to do and strill nothing, all the other files have what they told me to have and still error. plz someone help plz and thank u