The previous versions of Flash don't seem to like recursive functions. If you recurse more than 254 levels deep it thinks you're in an infinate loop. I don't know a way around this, but if someone does let me know. I wasn't able to test sorting a million number, but I was able to test 250 numbers.

Flash 8: 79 ms
Flash 9: 2 ms

Considerably faster then the up to 10 times faster that Adobe claims, but this is not your typical Flash application.