Broken tweens when Importing FMX Fla into F8

When I open/resave Fla’s that were authored in Flash MX in Flash 8 Pro I get intermittent broken motions tweens.
The motion tween looks intact on the time line but when you scrub it or publish the movie the tween is broken.
I think ive noticed the a trend though. Its seems to only happen to tweens that start a 0% transform or have motion easing applied to them. If I remove the tween and reapply it appears to fix it.

Ideas? How do i contact macromedia technical support?