I have installed Firefox 3 and after quite a bit of experimentation have discovered that Sitehound causes Firefox 3 to hang for arond 1 second every 12 seconds or so. I couldn't work out what was happening for a while, but after disabling and re-enabling other plugins etc, it was only disabling sitehound that solved the problem. Re-enabling caused the problem to return, so I've had to permanently disable it. Sound in videos continues smoothly but all graphics (including scrolling around pages) stops very briefly every 12 seconds or so which is rather frustrating. I had some difficulty installing sitehound initially (latest version downloaded yesterday), but it did eventually install, but does seem to affect the functionality of Firefox 3