I am assuming by your statement that you are able
to get web connections on other ports such as https.
Have you checked the IE Connections / Proxy configuration in
to see if there is anything listed there? (Popup killers and
personal firewalls can register proxies as well
as block ports so if you are running anything like this you
might try disabling it to see if the problem goes away.)
You also could have a virus or malware infection -- you
need to scan for these as a number of them interact with
web communication in an almost-always undesirable way.
Steve Duff, MCSE
Ergodic Systems, Inc.