If you haven't already, you need to install the Flash Player plugin. If you are on 64-bit, you need either Adobe's 64-bit Flash Player, or the 32-bit plugin with "nspluginswrapper"*
Which distribution are you using?
*Read carefully: nspluginswrapper, not ndiswrapper
I'm new to linux and learning as I go, but I've had little success with trying to find a way to get my music player and slide shows on myspace to function...