Mx.transitions.Tween

just got a quick question I hope you can give me some direction on;

ive been working on using mx.transitions.Tween lately.

so basicaly i have a frame looping from 2-5, 5 throws back to 2 if the target hasnt hit yet.

this is crude, and ill probably change it to setInterval or something later on.

on frame 2 it builds a nav item and animates it in.

however when i tried to setup a sub navigation, i got some problems.

ive structed the movie like this

level0 < preloader and main navigation
level0.buffer < sub navigation or content
level0.buffer.buffer < sub sub navigation or content

the first nav preloads itself and loads the nav in.
when i click the button to load the sub navigation in, the subnavigation acts, strange.

it appears as if the mx.transitions.Tween starts but holds in its physical frame 0.

eg my nav uses this to make an alpha tween from 0 to 100.

but when loading in the sub nav movie it appears to not load, i messed around and finaly changed the 0 to 50.

the navigation buttons appear in, but at 50% alpha, and dont carry on to 100% alpha.

ive checked that the subnav works, if i directly play it, its fine.

but if its loaded in via an mcl it doesnt work right.

the movie does play, eg; if i have basic created motion tweens on scene, they will animate fine. and the fact the nav gets built shows the timeline is executing, just the; mx.transitions.Tween, doesnt appear to be firing right.

any ideas?