Hi Anne,

This is Comcast interfering with you.

Comcast is dropping the connection by sending a RST packet when it sees that the upload is about to begin.

Upload Connections Keep Getting Disconnected, network is otherwise okay - Official Emule Board

I confirmed this report by bypassing my router and connecting directly to the modem. The packet exchange is as described above.

If I use a VPN, then I upload normally and get a better mix of Gnutella sources in my Shareaza client (Gnutella, G2, ED2K).

Comcast support seems totally unaware of this. It is very subtle, and I've investigated and systematically ruled out everything from Shareaza, to my network stack, my router, PeerGuardian, and Windows Firewall.

I even saw a Comcast-specific thread on this last fall, but I didn't believe it because it just wasn't happening to me.

Comcast Throttling? - DSLReports.com

This affects BitTorrent, Gnutella, and ED2K uploads, and the ISP Interference happens right after a range is requested.

This doesn't seem to affect BitTorrent when I use Protocol Obfuscation on another client.