I created a clean database just to hold the 3 tables used by this script. And everything seems to work fine for a while, and then I get the following message:

Later the message goes away and everything works fine.
On the same server I have another dbase with a forum (closed forum) that I only use to test stuff, and that works fine, even when this happens...
I'm going to take a wild guess and say that the script queries too much the mysql dbase. what's going on? any 'fixes' for this?