WRT54G to WUSB54G

I am connecting over a large distance between wrt54g linksys to the linksys wireless g usb reciever. I setup a foil dish around my reciever to help strenthen the connection. It helped a little. The problem is that it connects between 5.5 mbs to 18 mbs and it works fine but after a few minutes it will spike to 54 mbs and say its connected but i cannot access the internet.

have you tried using a 3rd party firmware that boosts the signal strength for the WRT54G/GS?

Thibor14 HyperWRT should give you some good gain.