Instantiating an Apple DLSMusicDevice into VE Pro Server causes it to crash eventually. It will crash if you try to delete the DLSMusicDevice or if you quit VE Pro after having used it at least once and relaunching VE Pro Server. Happens with both VE Pro Server and VE Pro Server 64. I can send crash logs if you can't reproduce on your end.
I am running OS X 10.8.2 and VE Pro Server 5.1.11548
For what it's worth, it does seem to work if you just build a new instance and insert the DLSMusicDevice and then never quit or try to delete it. But of course this is not too useful except for just trying out things.