Marc,
Yes I have tested and I can see the messages. Do I need to check how the serial port on DB800 board has been routed. Looks like the Config ROM expects it to be on 3f8 and take out from the Winbond Super IO. If the board has picked up the serial port either from the sourth bridge of else if its using some other port then that could be the reason for this.
How about the Video ROM image does it go after VSA or before that ?
Regards,
Phani