Back.easeOut Is Not Working But Strong/Regular.easeOut Is??

I have an alpha tween on my mcs. I've applied a Back.easeOut, Back.easeIn transition on them but it doesn't work, it prevents the mcs from tweening at all.

Strangely it used to work and it's only 'Back' as it works fine with other tweens such as Strong.easeOut. Any ideas??

UPDATE: ok I think the problem is with Back.easeIn. It only seems to allow Back.easeOut

sounds like flash is just being an arse.. it happens :(

:) Yeah strange. Lightspeed, any idea why you'd get rolling streaks on an image when fading?

I haven't the foggiest! Framerate issue maybe?

Tried changing the frame rate and it just changes the speed of the banding.