RossJ: The difference is due to differences in how the eventing is working in each browser in accordance with a windowless plug-in. I'm changing the menu now to make it smoother in both browsers and to lose the odd hover behavior.
vesuvius: Regarding search, on this specific page there are only eight videos available and they are listed down the right side. Therefore I don't think a search feature is necessary.
I agree tooltips would be much better than no information on hover, rather than having to click on each one to learn about them. This was pointed out by dshadle too (he also didn't like the current hover model), I just haven't added it yet.
rhm: which os/version and version of FireFox are you on?