Ok guys, /this is the thing. I have the same problem that all of you do. I have read, and heard lots of things about this, like is a DSL problem or Cable problem, or Vista problem, Firewall proble, Zone Alarm problem, Kerio problem, Norton problem or router problems etc... First of all, I don't have DSL, or Cable or Dial Up. I conect to the internet with my Blackberry. My problem started like 2 hours after I download and installed SP2 for Windows XP after I reloaded Windows. I use only Windows Firewall, and for Antivirus Symantec Corporate Edition which I have beibg using for the last 5 years without any problems.
I connected my Blackberry to a different computer, and the problem does not exist at all in my other laptop. BitTorrent works fine in the first laptop, anything download with no problem from any internet application, but Internet Explorer 8 or Firefox works only for the first 5 minutes that I am on-line, after that neither works.