It must the queries. Syntax-wise there's nothing wrong with them but it must be something. I recommend you print out errors generated by mysql_query, it might help to solve the issue or better yet do as the guys before proposed, run the queries directly in the database.

You can run the queries easily from phpMyAdmin or from command line if you have SSH access. Or you could just create a small PHP test page that connect to the database and run the queries and print out errors. Just don't use any user input, just fixed values that will give some results.

In this kind of situations debugging is usually the best option. Staring and analyzing your code tends to be quite hard. I know from experience that I tend to screw up with SQL and usually I create the query, run it on the database and then insert it into the code.