QL-browser problem

here's the story:

When im on www.quakelive.com, i join a server, i play, then i quit when finished and browser stays as it is, when i try to join a server again in the same browser window, i get lagged, firefox goes white and only thing to do is by ending the process via task manager.

that happens every time i try to join a server 2nd time in same window.

any idea what the fuck is going on? should i update/delete/download something?

firefox messes around.