Connected but can't go online!

Hello,
So here are the basics. I use SBC and have DSL. It goes through a router which then hoes itno my pc through the broadband cord. I have a desktop computer that uses Vista 64. Its all up to date and I am a geek so I know most things with the exception of networking.

So a few weeks ago is when this started. I was just at ABC watching a tv show when it stopped. I assumed it was nothing and closed Firefox and opened it back up. But when it opened it wouldn't connect to Yahoo (my default page). So I tried Internet EXplorer. And still no connection to it! I unplugged my modem as per the trick we all know and that didn't do anything. I tried accessing my "Gateway" program that comes with SBC but it wouldn't let me in (it uses the browser). No luck

Finally I left it for the night and when I came back the next day it was fine. Two days later it did it again! This time I scanned for viruses, spyware...etc. Nothing. I defragged, scandisked. After a restart it worked. A few day later....it did it again.

I called SBC. They ran tests and did a number of various things on both ends. They could see nothing wrong. I was connected as far as they could see. On my end I could even use my Xbox 360 and DSi to go online. So it was obviously something with my computer!

Well its been about 2 weeks and this problem now happens 1-2 times a day around 7am and 7pm I think. May be more random. I have no idea whats causing it. Its annoying because the only fix is to restart my computer and unplug the router every time and plug it back in...kinda of like a total reboot of everything. I've even tried using PeerGuardian thinking my compute was being hacked into. But seen nothing suspicious, although I assume I didn't see anything suspicious.

So can anyone help me? Right now I am out of ideas.

If it helps the only errors I get are from something called "Pando Media BoosteR" when I start my computer.