Losing all internet connectivity & torrents after a few minutes of use

[Goatboy]

I have not used bittorrent for a couple of weeks, but now I am having big problems with it. I have tried every client I can think of and every one has the same problem. I don't think I have changed anything (except download the routine Windows updates) so this is very annoying:

My torrents start fine; if I sit and watch them they will happily motor up to nice fast speeds (I have a 2MB ADSL line). After a few minutes (could be 1min, could be 5min) my down/up speeds fall all the way down to zero. It's not instant, usually takes about 30 seconds to fall fully flat. I cannot use the internet whatsoever after this has occured. No web pages. No MSN messenger. Nothing. Can't even connect to my router's config page in explorer.

I have to reboot the PC to get this all back.

I have noticed that if I start using the internet (eg browse a web page) as soon as I have opened uTorrent (or any other of the clients i've tried), my connection drops much quicker. Now I did the obvious thing and searched every forum I could find to look for a solution, so I have tried the following measures to no avail:

Disabled DHT in uTorrent.

Set my max no. global connections to a drastically lower number (25 is lowest i've been so far).

Set max no. connected peers per torrent to 25.

Disabled UPnP in my router.

Forwarded the uTorrent port to my PC.

Disabled Norton Internet Security.

Disabled the firewall in my router.

Upgraded router firmware to latest version.

Modified the TCPIP.sys file to increase max half-open connections to 50.

I have tried these all one by one, and all solutions together with no luck

This is my equipment:

Thomson SpeedTouch 580 router (it has wireless function but my PC is connected via ethernet cable)

2MB AOL broadband line

Windows XP SP2

If you need any more info please ask

[Ultima]

Disabling Norton is not going to work. You have to uninstall it (it's an extremely problematic firewall, by the way). Run the Speed Guide while you're at it, to make sure you set the max upload properly.

[Goatboywork]

I will try that, thanks, but I have been running Norton for the last 9 months and its caused absolutely no problems to bittorrent use in the past! Do you think an automatic software update to Norton might have amended the way Norton handles connections from other users or something?

(Also, its a bit ridiculous that I have to fully uninstall the software to remove its functionality! )

[Ultima]

Yep, that's just part of how software firewalls work. It makes getting disabled by malware a bit more difficult (though I'd say it's still pointless, but whatever =P).