I just downloaded the Vegas 4.0 demo (I've never used Vegas before, the interface is a welcome change from Premiere). Anyway, I tried a simple text overlay fading in over some DV video, and exported the resulting short clip. On the exported audio track there is a loud, harsh buzzing noise just as the title fades in. I exported just the audio as a WAV and opening that in CoolEdit, I see my original audio is replaced by a rough triangle wave during the transition.

Can I assume this is a "watermark" on the demo version of Vegas 4.0, and not a bug in the program? Otherwise Vegas looks very good and I'd like to upgrade from Premiere, but obviously it won't work if it destroys my audio with every transition.