Hmm... this isn't looking good. Sounds like a Movieshaker problem. You might need to reinstall it from your camera's disk. Reading other sources about Movieshaker, apparently it comes preinstalled on some PCs and when used with a Sony DCR-IP7E, it needs additional bits only found on the camera's version.
Also, reading sources on the internet indicates the native MPEG-2 format of the camera gets transcoded to DV-AVI for editing by Movieshaker. If you can find the original file downloaded from your camera on your hard drive (I have no clue what suffix it uses), you should be able to copy and rename the copy's suffix to .mpg and then play that in Windows Media Player. If that has audio, then it's definitely a MovieShaker bug.
Fav quote - "Experience is whatcha don't get 'till ya don't need it no more."
System - Athlon 1.4GHz, Win98, Hauppauge PVR250 receiver and compressor.
Software -Magix Movie Edit Pro 10, Nero 6 + NeroVision Express, Moho 4.61, PSP 8.1, Bryce, Quicktime 6.52 pro, Goldwave 5, DVD-Lab.
Cameras - Panasonic GS9, Canon ES8400V, Canon EOS D20 and Canon A70