modules problem

HI iam using postnuke 0.750 rc4
PHP 4.3.9
apache 2.0.52
on fedora core 2
and i have problem with some modules
like myheadlines 4.2.8 pnuserpoints and etc
the problem is that i initialize and activate the modules
sometimes i can see the new module on my admin panel and when i try to access it i get an access denied error sometimes i even didnt see the new module
any idea please
register globals on my php.ini is set to on
well know can help me here with this problem?
ya gotta read the how to manual at http://www.jmagar.com
It's yoursite.com/index.php?modules=MyHeadlines