Flash on Mac publishing problems.

I've been using flash mx for a few years on my PC and just bought a new mac a couple of weeks ago and installed flash 8.
If I open my files from my pc (in mx) it all seems to be working well except when I publish preview a project, everything is unaligned.
It all looks right when I'm editing put when I preview or publish it goes all funky.
Some things move up a few pixels some move across...
My only resolution so far is to publish preview, see how far I need to move the graphic.
Close the window and make the adjustments then test again.

Does this sound like its a problem moving the file from mx to flash 8 or from PC to windows?
I haven't experienced this problem with files that I have created on the mac, only the ones I created on the pc.

Thanks