Comment 31 for bug 192888

D4nielfree: as far as I know: flashplugin-nonfree is the flash plugin itself (in fact that ubuntu package is only a downloader/installer for fetching the flash plugin from adobe through the Net and install it), while libflashsupport is for support flash to be able to play audio through PulseAudio sound server which is a core component of Ubuntu Hardy. So if you remove libflashsupport you loose the ability of working through PulseAudio. If you have a sound card which capable of playing multiple streams by hardware it's not a problem, however not every sound card is from this type, and also the basic idea of PulseAudio (and its role in Ubuntu Hardy, and also in other distributions like Fedora - as far as I know at least) is to have an audio server to be able to control all audio sources and mixing together then.

Ok, if I'm wrong in my explanation somewhere, please correct me!!