Yea. I also got the same problem... I tried with Apache proxy, and still doesn't work.. I think its something wrong with BitComet. Did you check BitComet with any other proxy?
I've configured BitComet to use a HTTP1.1 proxy (the only other options were for SOCKS proxies) and it doesn't seem to work. I've manually tried telnetting to localhost on port 3456 and issuing ...
I'm required to use an anonymizing proxy (Privoxy+Tor) in order to bypass my ISP's attempts at blocking BT client traffic. How can I continue to use GT?