Ahhh… the “Internal Browser” is the embedded Web Browser component in Eclipse. You can actually access it under Show View > Update Manager. On Windows its a wrapper around IE, and on Unix there is no equivalent for 2.x series, but in the 3.x series they are testing a wrapper around Mozilla, however it is flaky at best.
Try and open that view and see if you get anything to show up, if you don’t you can setup a different default browser here: Window > Preferences > Install/Update, and also look under Window > Preferences > Help.
Note that I’m using 2.x series, so it may be drastically different for 3.x