When using RaiseBubbleEvent(source, args) in my Parent Page OnBubbleEvent is called twice!

[Andreas Klemt]

Hello,
why is OnBubbleEvent on my Parent Page fired even when I didn't do
RaiseBubbleEvent in UserControl Page?

When I Call RaiseBubbleEvent in the UserControl,
OnBubbleEvent is called twice in my Parent Page.

What is wrong?

Thanks,
Andreas