Ethernet issue: works one way but not another

[John Allesee]

This one has got me stumped.  Been working on it for 3 days now with
no resolution.  Please help.

I have a 686 system that I just installed 5.3 on through ftp.  So I
know that my network setup works.  I have 2 networks that I am trying
to access through.  One network is connected to a 100mb 3com hub using
private ips into a firewall.  This one works with no problems.

The problem comes when I connect the system to the other network. This
network is connected through a Breezecom wireless radio at 10mb.  I
can see that the network is up, ip address is assigned, routes are set
correctly.  Pings time out.  No traffic appears to cross from radio. 
Plug windoze box to radio, works fine.  Plug radio into 10mb hub and
plug FBSD server and windoze box to hub, same results on both.  I can
ping FBSD from windoze.  FBSD still sees nothing.  If I run tcpdump,
wait 10 sec, hit ctl-C, nothing happens for 2.5 min.  1 packet is
displayed and exit reports 1 packet captured, 6775 packets received by
filter, 6094 packets dropped by kernel.

I have tried 3 different network cards, each has the same results.
Card 1: 3Com 3C905B, card 2: SMC 9432TX, card 3: Generic 10mb card by
Realtec

I know that the obvious answer is to connect the server through my
firewalled connection, but I have a need to access another part of my
company network from my desk and the wireless net is the easiest way
to do this.

Any and all help is greatly appreciated.

TIA,