I think it’s a video/audio codec issue. Codecs are truly a nightmare, if you install one it breaks five others. I’m having the same problem, video but no audio. So I uninstalled all my codecs. Then I get audio but no video. I install the single codec I need for my video, divx, then I get video but no audio again. Just great. I’ve also tried different codec packs with various bad results.
(Of course I tried saving with the audio working then importing video once that part is working but it will no longer read the working audio.)
So… if anyone works this out please post it.