Sony DVD Architect menu question…

Hi – I have a question re: Sony DVD Architect (4.0):
I created a menu using an animated background (Sony’s Heaven in Motion) which is an .avi file.
When I preview the menu, after about 10 seconds, the menu background turns black and stays black. The buttons and titles still show and are usable, but lost the animation.
I tried end action (loop), but that didn’t change things.
Any help greatly appreciated.

p.s. would also like to here about sites where animated backgrounds can by purchased or downloaded.