Layers disappearing

Hello guys,

I made this webdesign in PS
Then I saved every layer in a separate png file and put each of those png’s on it’s own layer in flash.
Now everything goes well till I get to the 12th layer…
The moment I want to make the 12th layer visible the bottom layer magically disappears. Can you help me with this annoying problem (bug?).
The flash file if you wan’t to check it: http://butchersinaction.com/schampi/webdesign/juli2005/juli2005.fla

Thanks, ScHAmPi.