Personally, on something that you EXPECT to lock up at some point or another (C'mon! You weren't SERIOUSLY expecting it to work flawlessly, were you?
), you really need to concentrate just a little bit harder on remembering what it was you did just before the lockup...
I know it's a PITA, and detracts from the playing enjoyment, but with the Audya in its' fragile state, Ketron probably need as much intelligent informed feedback as is humanly possible, to better help them squash these bugs. All it might take is ONE user to report a reliable sequence of events that causes a lockup (including the speed at which you make OS requests), and they MIGHT be able to squash the bug once and for all.
Having accepted the responsibility of being a 'beta tester' whether you knew it or not
by buying the damn thing, given how good it sounds, knuckling down and making a strong effort to remember EVERY button push and OS call (even more than what chord you play or melody you play) will probably in the end result in you starting to have some real confidence in the product as Ketron fix the issues.
I went through the same process with Roland (although no bugs were able to freeze it), and a community of users determined to assist Ketron find and squash the bugs WILL make the instrument better. It just takes patience, determination and concentration (especially while you 'noodle'). I helped run the G70 Bug Forum, and can assure you that it CAN be done. It's not enjoyable at the time, but after the bugs are fixed, you can enjoy playing in the knowledge that, in whatever small way you got involved, YOU were a part of that enjoyment...