Unique to say the least
Well you certainly straddled the line there between cute and disgusting a few times, and I don't get the impression you've studied rhino's much, but who cares? I doubt I'll ever see quite the same take on a hungry animal. You had some good animation in there, and the plot was clear and whatnot. I don't really get what the plants with food bait were supposed to be, if anything, but it's a minor issue. It's good stuff. (4/5, 9/10)
As for your supposed sound problems (if you're still worrying about it), I can't say for sure, but if you're getting a message from flash about a sound related error when you export, it's probably a certain sound or frame causing your woe. If you can isolate where it is (delete scenes, parts of scenes, etc until you don't get the error when you export, delete smaller sections over time until you find the cause) you can fix it by changing the sound from event to stream or even by moving it to another layer. I can't guarantee it'll work, but that's my advice. Hope it helps.