Evidently I am a complete fool

So I got my new D-Link G624T wireless router (hope this is the right place for this). I plugged everything in how it tells me to - I'm running a Windows 2000 machine.

So after I've set everything up using the "quick install", I access the thing online, the setup. I then try and connect with my laptop downstairs - but it keeps on connecting, then disconnecting, then connecting. The lights on it all stay green, except the status one which flashes - though I read it was meant to do that on the site's faq.

One final thing. It won't let me access some programs that use online - Adobe's automatic update, iTunes online store or MSN.

Can anyone help me? I checked all my settings and they are right... but I feel I have missed somethign simple.

Any help appreciated.

Even stranger now... I've connected to it wirelessly - the wrong password, silly mistake.

But on THIS computer (and only this one - the one downstaris lets me access) online programs don't work - iTunes, MSN or acrobat are the ones I've found so far.

I'll try a firmware update... but apart from that I'm stumped. Perhaps the built in firewall? I'll have a look around...