Ok it is plusnet, not all is lost (I use them as well), what package are you on? Value by any chance? If so then you will be limited to 30K max (from memory) as it is sold as "Not suitable for p2p or usenet", I use unlimited and find it fine so far, full speed 12 hrs a day then various lim...

What ISP is it?
Some like plusnet in the UK throttle based on packet type so changing port doesn't effect the throttling, your only hope may be moving ISP again if possible.

Just installed Deluge again to test the new version, OS is Ubuntu 64bit 8.10.
I can't seem to disable DHT, even if I UNtick the box in the options it is still ON. How do I turn it off ?