Vista - Can't get 360 and media center to connect

Ok, so i've been working on this for awhile now and i'm at a dead end.
Here is my issue, my machine is running vista x64 ultimate and for the last few weeks, I have not been able to get my 360 to connect to my pc. When i actually turn the 360 on, I get a notification in the taskbar and when i go through the steps to set up my extender, it always fails at connecting to extender. At the same time, the 360 just sits at the contacting screen with the white dots and eventually fails.
I'm only using the windows firewall, which i've disabled and still have had no luck. I've also connected the 360 directly to my pc to no avail with 3 different ethernet cables and i'm pretty sure its not the network or my 360 itself because my xp media center works just fine. At this point, I've narrowed it down to my vista machine, but i'm at a loss.

Any Ideas?
Thanks.

Sounds like it might be a router issue. What router do you have?

I've got a Linksys WRT54GS with FW 1.06.3 (Mar 2008) , but even when I bypassed the router and just hooked the 360 directly up to my pc, it still didn't work, Same error.

interesting. Maybe you'll have to forward this problem on to the XBOX forums on Microsoft's website.

I'm at a lost here since I don't use the Media Centre function in the first place.

Maybe..