iTunes won't connect to the internet...

I just previosly upgraded to iTunes 7.7, since then I havn't been able to access the iTunes store. When I try to access the store this message comes up: "iTunes could not connect to the iTunes store. Make sure your network connection is active and try again." I tried reinstalling iTunes, restarting iTunes, restarting my computer, clearing the DNS settings, and I checked to see if iTunes had been blocked by my firewall software and it hadn't. I don't know what else to try, and I can access it through my Ipod Touch, which is no use because to both log into my account and add credit onto my account I have to access it on my computer. I'm able to access other online programs such as internet exploror and AIM. I can still get to my music library and my playlists, just not the store.