INdeed it would be good to have a recipe for disaster. I am having two problems constant with GEM keyboards.
1) A tone (note so you will) keeps hangning. Changing the perf, style or song doesn't help. Maybe the keyboard puts the call for a certain note in it's int memory, and after many requests/threads the OS is a bit unstable and a thread is forgotten to be ended (in other words; the OS doesn't say, he I played it, remove the request for that tone)

2) Lock-ups. My personal recipe: Go change all sounds with sysex commands, and as many samples as you can. Play than eg with a hammond sample a funky solo. Bount to freeze. Also when changing a lot of parameters in the micro-edit, esp. with the undo function on. My personal record is about 25 changes, and than the WK4 freezes. You can also have troubles when loading WAV samples. The WK gets really sticky slow after loaded 4 WAV samples and then trying to assign them

I don't have hope GEM will work on this for releasing a new OS for the WK4. I pray that in the next keyboard (WK8plus, WK10 or something) the put in a RISC Alpha Processor/Intel PII/PIII for loading and doing al things other than processing sound. And a sound-proccesor next to that. That would solve most of typical GEM problems. I think ;-)

Greetz
Joost