I don't quite understand how ADDING another box helps things out.. Did you disable the SPI firewall on the D-LINK, and use the NETGEAR for that?
I'm kind of confused how adding another hardware firewall/switch between the router and PC helps (I don't DISBELIEVE it, just don't understand the concept). Presumably the D-LINK is still doing DHCP for the system. Is the D-LINK forwarding ports to the NETGEAR which then forwards to the PC, or does the D-LINK still FWD directly to a PC, with the NETGEAR just sitting in between re-filtering all the traffic?
Maybe it is the VPN capability that makes a smoother connection between the WAN and LAN IP's...
Interesting....
Recluse