I used the SQL from phpMyAdmin and entered the following code:

DROP TABLE IF EXISTS `hide_categories`;

then POOF! all my products were gone from the site. I deleted all the files and/or code related to the Hide Categories add on module. Everything else looks fine. Although the original category (only one) that was hidden is still hidden. But as I mentioned earlier, the RSS feed shows all the products.

I double checked all the files, compared them with beyond compare and everything SHOULD be OK...

Thanks