I have also the same problem but I solved.
The problem is in the query sintax.

I'have used the sintax for php that propose me phpMyadmin like this:

INSERT INTO `dbname`.`table` (`id`, `username`, `password`, `score`, `msg`) VALUES (NULL, \'michey\', \'mouse\', \'700000\', \'hello world\')

and now work fine. No "error in engine".

Sorry I forgot:
I use a7.10 Pro edition and MySQL: 5.0.51b-community-nt

I hope this is useful.