I've been fidling around with the trial version of flash (just 'cause) and I've noticed that I've been getting progressively better. In my first flash, which was a sprite flash, the sprite came off center a lot, so it was really shakey. But in my most recent flash, which is still a sprite flash, the sprite is stable and the animation is fluent and it doesn't look shakey.
Note that I'm not at all professional at this, I'm just your average guy, and I've only done 4 flashes.

First one...
And... uh...
I have some animation issues with the more recent one. I'll get it to you guys ASAP.
sweatdrop