cannot ping across wireless link

Having trouble with a change from 2000 server to 2003
server

We have 2 switches located either side of a road and
connected via a wireless link, effectively one lan

We use terminal services to access the server from the
remote link (over the road)

All worked fine with 2000 server but not with 2003
server, I cannot get any access across the wireless link

I can ping workstation to workstation on opposite sides
of road

I can ping workstation to 2000 server on opposite sides
of road

I can ping workstation to 2003 server on same side of road

I cannot ping workstation to 2003 server on opposite side
of road (via wirless link) times out

2000 server is the DC

dhcp from adsl modem

Is there an added feature in 2003 server restricting
access via the wireless link

Is there any other reason this may not be working

Thank you