So I installed the patch Steven posted 2 post earlier, and the playback started freezing again. So I went back and reinstalled 2.3.5153 beta and recopied the second .exe file (
http://www.mediafire.com/download/1m68g2i01r8751z/MusicBeeDebugAsio2.zip) steven posted and its back to working again. Not sure if its something in the .dll, or the xml config buggering things up.
To sum up: 2.3.5153 + 2.3.5160.28883 (exe only) seems to work. Full 2.3.5160.28883 patch does not.
Gotta say thanks to Steven again. I've always been impressed that 1 person is willing to put in the effort that entire corps. can't be bothered to.
<edit> After a bit of experimentation copying the patch files individually, I discovered it's the exe file that is breaking things. Kinda strange since the version in the above mediafire link is the same number as the one in the patch, although there is a small difference in size according to windows prefs.