Dell 802.11n Wireless Mini SLOW Wireless

I have a Dell Inspiron 1520 Laptop and stuck windows 7 RTM 32 bit on it. All was well but now connecting wirelessly is slow. Like slower then 56k modem slow. I have a Dell 802.11n wireless mini card installed that works PERFECTLY under windows XP. I was getting 80 % signal strength under Win 7 and getting 1 mbps where as in XP I was getting 78 to 100 mbps with the same signal strength. Oh and ethernet works perfectly fine.

For a time I was able to download the corresponding vista driver from dell and then replace the driver that win 7 automatically installs for it, then flipped the card switch off and on and it would work like it should for a while, but then reverted to the same slow network speeds once the laptop was reset or turned off and on. Now flipping the switch or re-installing doesn't work either. I've tried resetting the router, no go and none of my other computers or products have a problem with it. I've tried doing a few things suggested in other posts, like assigning a static ip, disabling ipv6, etc... Nothing has worked.

I'd love someone who knows what it may be or has heard of this precise problem, although I think I may be stuck waiting until Win 7 makes it debut in Oct and until Dell releases a proper 7 driver for it.

Laptop: Dell Inspiron 1520

Wireless Card: Dell brand mini draft 802.11n card

Router: DLink DGL-4500 draft 802.11n

Windows 7 32bit RTM