Firewall/NAT

I have a mix of windows, linux, and mac users in my office.  We have the m0n0wall set up with 2 static routes, that direct WAN and LAN traffic for a network through a second gateway.  My linux and mac users have no problem using these routes.  Windows XP machines will only work if windows firewall is disabled, and windows 7 machines will not work at all.  This is for using SSH to access servers in a datacenter.  The alternate gateway sends the requests to the corporate VPN tunnel.  I am not sure why windows is having a problem with these static routes.

m0n0wall gateway - 10.4.182.254
alternate gateway - 10.4.182.1

It sounds like there is something going on besides the static routes. On the WAN interface, do you have the box to 'Block private networks' UNchecked? How are you assigning the gateway to your clients? DHCP? Or statically? Are the Windows machines picking up the proper gateway (m0n0wall)?