[flexcoders] getting/settings explicit height/width for a custom toolTip?

[djbrown_rotonews]

I'm attempting to create a custom toolTip using a Text component (of 
varying length, depending on the underlying data) inside a VBox 
component (with no explicit height or width declared) that implements 
IToolTip.

Inside the creationComplete handler for the VBox, I build out the 
contents of the Text component, but the underlying values of 
measuredHeight etc.. don't seem to get updated. As a result, the 
toolTips aren't being posiitioned correctly as calls to 
getExplicitOfMeasuredHeight and Width is returning values like 6 and 7 
as opposed to 225 and 150 etc...

I've even placed explicit calls to invalidateProperties, 
invalidateDisplayList and invalidateSize at the end of the 
creationComplete handler with no luck.

any ideas?