I have an old MIDI-only patch that I've used as a demo for years. It has always worked fine through countless Max and Mac OS updates ... until Snow Leopard. I'm still using 10.5.8 on my own computer as well as in my lab at school -- no problems. But students who have Snow Leopard installed are unable to get any audio playback through AU DLS synth when they try to use it.
The problem exists on multiple Snow Leopard computers, with multiple versions of Max, with a simple patch file, with a collection, and with compiled stand-alone applications ... whether compiled on my machine or on one of my student's machine. Of course, solving this is complicated by the fact that I don't have a Snow Leopard machine of my own to test on. Any ideas?