Causes for browser freeze on webplayer close

Hello! I am using lidgren to program my own networking library. I am coming across a rather annoying problem... Whenever closing my game inside the web browser, the browser freezes! I managed to fix some of these crashes by calling Netclient.Disconnect(), on a hunch -- But after having added more functionality (particularly notfications form the server of other users coming online) I have been having more crashes. So this leads me to my question: What are the common causes for browsers to hang when the Unity webplayer closes. I'd like to know what resources I need to be closing down in order for a smooth exit.