Looking for an Event

Hi,
I’m writing a Flash app (momentarily using AIR), and I’m looking for an event to fire whenever changes are made to a displayobject’s properties either through code or through animation on the timeline, so I can blit some vector graphics more efficiently, rather than BitmapData.draw-ing a bunch of frames that are exactly the same. Are there any events that do that?

this mx.events.PropertyChangeEvent *sounds *like what I may be looking for, but my compiler doesn’t recognize it - it looks like it may only be available in Flex (which I’m not at all familiar with), which seems strange to me.

Help?