I've been having slow upload with Deluge 2.1, but I always attributed that to my new vpn provider potentially throttling certain traffic. It didn't quite occur to me that a Deluge configuration could be a culprit as it cooperated in the past.
To your knowledge, does Deluge use any uncommon network ports for torrent upload? I'll have to look into this in any case.
Grog XD anyone?
;)