I've noticed that when my BEFVP41 router is acting as my gateway my internet speed drops from 4 Megabits a second to less then one, but if I use my wireless G Router as the Gateway its fine. I've been racking my brain on what could be causing this problem.

Also is their anyway to get the BEFVP41 VPN router to work behind the Wireless router if I cannot find the speed related issue with the router. I am running the latest firmware.

it could be the double nat firewall between the two routers.try to use the vpn router as your gateway and then make the wireless as a switch only.