Bizarre connection problem

For the last couple days, I haven’t been able to connect to any torrent trackers or eMule’s eD2K’s network. This began totally out of the blue.

The weird thing is that not only can I can do regular navigation just fine and direct downloads work perfectly, I can still make torrents work through DHT and the Kad network still connects. uTorrent tells me I’m perfectly conenctable to incoming transmissions, however, I do fail eMule’s TCP connection test*. I’ve taken some random speed tests that connect perfectly even through P2P ports.

In short, when connecting to either trackers or eMule servers, they all time out. Everything else works fine.

Strangely, at random times in the day, things begin to work, then break down again.

My provider claims nothing is wrong, but I honestly have no reason to believe them. I’ve still ran every spyware/virus check I’ve got and I’ve enabled/disabled Windows’ firewall over and over to check. Nothing.

Ideas?

*EDIT: Okay, something more on this one. If I manually change the TCP port, the test goes through, but i still can’t connect, and if I wait a moment and try the test again, it fails just like before.