When recording the files are written as Quicktime files. You really don't need Quicktime Pro, that's really just not true.
The Quicktime files are compressed with the Photo Jpeg codec with highest possible quality. We didn't offer a way to set codecs because it allways seem to be confusing to people. Now you just press record and off you go. There is no support for .avi files because it has to be cross-platform.
Quicktime files play much better now in Resolume 3 then they did before in version 2.
O.k about the 0 bytes issue, that's weird, you say that it works on your other machine without problems?
Does anyone else experience the same problems? You might want to check though if your harddrive has still enough space to store your files.
But if you find some more clues to find out why it might work let us know. It's quite hard to reproduce these kinds of bugz.