Flash animation

rmg1

I've got some Flash animation (made with Flash, it's not that good!) that's gone a bit weird!

Basically it's a frame of text that appears to spin towards you (if that makes sense). It's basically the same frame resized with tweening set to motion so you get an illusion of movement.

Now for the weird bit.

While the text is upside down, it's as smooth as you like. However, when the text is the right way up, it goes very jerky.

I'm exporting it as a movie (.AVI file) using File/Export/Export as Movie and no matter what I do I can't seem to smooth it out.
I've removed the video compression, made sure that the "Smooth frames" (I think it's called) box is ticked and tried everything else I could think of.

Any Flash Gurus out there willing to lend a hand?

I can send the file over if you want to have a look (as long as nobody starts laughing! )

rmg1

Anyone, please?