Showtime8000 ,

I dont think your problem is related to routing. Especially if your router is routing unicast packets without any problems, and you are not filering any ports...

Try scanning someone local (get another PC if you have one) on same LAN to eliminate configuration/application issue.

Cheers.


P.S
Showtime8000 , a router does not by default modify a packet in any way. It routes packets based on dst IP address period!!!!!!