Unity webplayer crashing browser when it is loaded and unloaded into a page using JavaScript

We're using a small unity webplayer client to show a player's avatar on their profile page. As the user can move around their profile (view friends, set settings etc) all using Ajax based methods we're using javascript to remove and add the webplayer to the DOM when and where its needed. The problem is is that we're finding that the webplayer crashes the browser 80% of the time when working like this.

So my question: Is this a known Unity Webplayer problem or is there something that we're doing incorrectly?