I've had alot of trouble getting Java programs that are embedded in websites (e.g. the photo uploader on facebook, and more importantly, the scheduler for my job) Originally, opening a page with Java would cause Firefox to close very suddenly, so I installed a couple more Java packages, and now it loads the page, but when it gets to loading the applet, instead of crashing, Firefox goes dark and locks up.

Here's some of the java packages I have installed, I'm not sure what's relevant and what's not, so I'll list things that don't look like dependencies:
sun-java6-jre
sun-java6-plugin
default-jre
openjdk-6-jre-headless
openjdk-6-jre
cacao
gcjwebplugin

My best guess is something I overlooked, or some conflict between openjdk and sun... (with just openjdk was when it would just crash though)

Thanks,
David