I only ask about 48K because I made a new discovery. For years I've video recorded live bands with miniDV camcorders, and a separate soundboard audio source using a digital field recorder. I had the field recorder set to 16B 44K. I would then import the video to my computer via Firewire, and with it being digital video (or maybe all video being imported) Vegas sets the quantization & sample freq at 16B 48K. Once I started the editing of the multi-camera show, (all of the camera angles and the soundboard audio synced up), I noticed the board audio drifted a bit from the camera audio. Then I recorded a show at 16B 48K, and the board audio didn't drift at all from the video audio.

I'm currently working on a Despecialized ANH, using the BD for the video and the '92 laserdisc for the audio. I imported the LD at 16B 48K, and so far it's synced up pretty good to the BD. I can't help but wonder if it would not have had I selected 44k? When I check the Properties in Vegas, it shows the 6.1 DTS audio from the BD is at 48K. And that's why I'm wondering if you're working with audio for video, if it needs to be sampled at 48K.