It sounds like either an INSERT or a SELECT problem. Have you examined the rows? Do the different users have different cookieIDs, et al, in the row for their items? If not, then clearly it's a problem with the way you're assigning cookieIDs. Otherwise, it's likely a SELECT problem. For some reason your WHERE clause is choosing all records instead of only the ones matching the current user. Echo your query and see if it looks like you expect it to.