home premium 64 - lan but no net

hi all, i have vista troubles and would appreciate your help. i’ll put up all the info:

i just installed vista home premium 64 (OEM) on a new gaming system. i can access my local network normally (file copies, etc), but i can’t access web pages (thru IE or firefox). oddly, i can connect to the steam gaming services, ie log into steam, update games, even join net games. after i do that, the tray icon shows "local and internet", where it was "local only" before.

the addresses are the 10.0.0.xx kind.

i’ve tried the diagnose function, but no help there. the rest of the systems on the network (wired and wireless) can get on the net, they are all XP systems. my firewall is off, net security is on medium (lowest setting on the slider). i’ve tried disabling net 6.0, no luck. tried the vista update but it wouldn’t connect. my nvidia network drivers are the latest.

i’ve tried restarting the routers and my system a few times, tried disconnecting the ADSL access (to isp) and reconnecting, tried ipconfig /release/renew. release returned "that operation requires elevation".. or whatever…

my network goes like so:

phoneline on wall
to
ADSL router (alcatel speedtouch pro) - DNS and DHCP srvrs running here
to
d-link DI-524 airplus-g
to
- 3 wireless xp lappys
- 1 xp desktop
- my vista desktop (wired)

ipconfig shows that it’s found the correct gateway - the 10.0.0.xx address of the speedtouch.

i noticed an odd route in the speedtouch’s route table:

Destination Source Gateway
default 10.0.0.25/0 [our isp assigned net address]

25 is the local address of my machine… no other systems on the network have routes in the table matching this one.

(if it’s at all relevant…)
my system specs are:
VISTA home premium 64, straight off the CD
EVGA nforce680i (with dual gigabit lan - tried each port, same results)
EVGA GTX8800
4GB crucial ballistix ram
2x WD 400gb - raid 0
intel Q6600 quad
ASUS 1814BLT lightscribe DVD (currently causing BSODs after win logo when booting… hard to update the firmware when it won’t even boot!!)

so yeah… seems like something to do with vista’s setup, since i can access steam! i’m at the edge of my knowledge here, any suggestions?