Vista - Slow Down - Half - Howto fix audio speed?

Movie Maker seems to try to keep sounds the same pitch when accompanying a
slow-down-half video clip - In WindowsXP's movie maker, the sound's pitch was
slowed down relatively to how far the video clip was slowed down - In Vista,
it tries to stretch the sound to cover the slowed-down clip, and creates a
very ugly echo-effect - Does anyone have a solution to this?

Thanks.