Audiomulch 2.0.3 is frequently hanging for me when I switch between files. It doesn't seem to be all files, but I'm not getting any specific Audiomulch errors to follow up with.
Windows goes into "(Not Responding)" mode with Audiomulch whenever this happens, and I've only noticed it since 2.0.3. I'm running Windows Vista home (which is probably half the problem), but I have no idea how to troubleshoot what else could be causing this. To get out of it I force AM to close and then reopen.