@Massimo Banzi: no, i installed the connector by myself because i was in need for a possibility to flash the chip.
@Stephan Watterott: ahh, perfect. i already tried to reach you by phone 
backside of the duemilanove comes here: duemilanove4.JPG. please ignore the bad soldering points at where the additional 4 pin connector is. i didn't have the best equipment when i made it. lighting is a bit bad at this hour but i hope you can see most of it. I also sent an email to you through the contact form in your webshop.
[update]
okay, it seems as if the wrong crystal was put on the board.
Mr. Watterott gave me choice to exchange the whole board or just send me a new 16MHz crystal. I chose to take the crystal and solder it in by myself. So everybody's fine again and i can go on with work