note 26645 rejected from ref.mysql by tix

I wrote a script prior to the major changes in 4.2... it had its own user system which relied on mySQL and a messageboard which also ran through mySQL.... I've been trying to get it to work with PHP 4.2 and I have managed to get almost everything working, except for one thing, when someone is inside their account, they are free to roam around until they add or update something in mySQL, as soon as they do that it looks like PHP is destroying the session.... does anyone have any ideas?