Problems importing ac3 in Vegas Pro

[mltwitz]

Vegas Pro (running Version 9.0b) will not import vob or mpeg files with an ac3 audio stream properly on my machine. What happens is, that it either freezes or it imports only a short section of the clip. I have to first demux the audio from the video convert the audio to something else an then import works...very annoying. Is this a known issue or is this a unique problem I am having? Vegas Pro does support ac3 rendering, why wouldn't it then support importing ac3??