port forwarding woes

Hello everyone
I've got an ADSL router plugged into a DLINK router and am trying to
access my webserver from the outside. I've forwarded the port on WAN
side of the modem e.g. 210.233.423.222:888 to the router on the LAN of
the modem e.g 10.0.0.1:80. I've then forwarded the WAN of the router
(10.0.0.1) to the LAN of the router.

When I type in 10.0.0.1:80 on my lan I happily see the served webpage,
so the router is correctly forwarding this. However when I type in the
external IP&port I get "Page not found" (this is getting forwarded
through the modem and the router)

Looking at the log of the router I get this curious message:

Jun/30/2006 23:32:40 Drop TCP packet from WAN 10.0.0.1:800
10.0.0.1:62026 Rule: Default
Jun/30/2006 23:32:31 Drop TCP packet from WAN 10.0.0.1:800
10.0.0.1:62026 Rule: Default

I know this is the firewall on the router blocking this request, but
what I'd like to know is why the source IP 10.0.0.1:800 is being
translated to a destination of 10.0.0.62026 (the port changes every
time I click the external link). If I unblock the firewall I still get
no webpage but obviously no error in the log either.

I think this port change between source and destination is my problem,
I just can't see why it's happening. Could it have something to do with
the IP routing on the Modem??

thanks for taking the time to read this, any help would be appreciated