Can't connect to my Billion 7100G wireless router

Hi,

I just bought a new laptop with MS Windows Vista Home Premium pre-installed,
and came home to connect it to our wireless network. This seemed to be far
more complicated than I first thought.

When I try to connect, it returns that my WPA is wrong, even though I know
for sure that it's correct, as I also use the same WPA for my XP computers.
I've also tried to change the WPA through my router administration panel, but
with no luck for the Vista computer.

My router config:
Encryption: Enabled
Key Length: 64 bit
Auth. type: Shared Key
Passphrase: <no text entered>
WPA Mode: Enabled
Network authentication: Pre-Shared Key
Data Encryption: TKIP
WPA Pre-Shared key: <shouldn't post that>
WPA Group Rekey Interval: 0

Please help me out with this, so I can keep Vista. I like the OS, but it
needs to work...