if you have preloader, use the hack to block disc updates if you dont have preloader, go grab startpatch for 4.1e and enable it in there.
gecko os thing will make you do it every time you start the game
but you also might want to make sure you have the newest ios53. you can either extract it from your disc, or use nusd to grab a wad and install it, or use dop-ios to install it(dont trucha bug it)