One Win7 computer on network having internet problems

[knilsilooc]

OS: Windows 7 Home Premium

Computer: Dell Inspiron E1505

Connection Type: Wireless Bridge (Wireless + Ethernet)

Wireless Card: Dell Wireless 1390 WLAN Mini-Card

Router: Linksys WRT54G v8.2

I've been having this issue for about a week or two now, and I'm quite tired of it. I've had Windows 7 installed since a few days after it was released to retail, and now all of the sudden I'm having internet issues. While other computers on the network (of the Vista and Win7 variety, PS3, DS, Droid) all can connect perfectly, this one just doesn't like to cooperate.

When first booted, the computer usually works fine, but then all of the sudden, the internet becomes very slow. It's almost unusable, though it's still possible to instant message. That is, until it decides to stop working completely. Usually disconnecting and reconnecting to the network fixes this for a bit, and restarting helps even more. No matter what, though, I'm still disconnected in the long run. I've searched far and wide, and I just can't figure out why. Some of the things I've tried:

- Removing the wireless adapter from the network bridge (it's bridged to give my Xbox 360 a wireless connection)

- Reinstalling the wireless card drivers

- Changing Antenna Diversity

- Disabling the Function Discovery Provider Host and Function Discovery Resource Publication services

- Scanning for spyware and viruses (MSE, Spybot, Ad-Aware)

- Cleaning the registry (CCleaner)

Nothing I try works. This is a computer that worked just fine while WinXP was installed, which makes this all the more frustrating. Also important to note is that starting the computer in safe mode gives the same results. Does anybody have any insight into this at all?