Is this you by any chance?

2013-04-29 16:39:08.307039 Incoming connection to peer 74.100.64.248:56708 established. p2pool version: 1100 '11.2'
2013-04-29 16:39:08.472251 Sending 1 shares to 74.100.64.248:56708
2013-04-29 16:39:08.474522 Lost peer 74.100.64.248:56708 - Connection was closed cleanly.
2013-04-29 16:39:08.475089 > in handle_share_hashes:
2013-04-29 16:39:08.475163 > Traceback (most recent call last):
2013-04-29 16:39:08.475245 > Failure: twisted.internet.error.ConnectionDone: Connection was closed cleanly.

That particular peer is having a lot of trouble:

$ grep 'Lost peer' log | awk '{print $5}' | sed -e 's/:.*//' | sort | uniq -c | sort -nr
 168 74.100.64.248
   5 123.159.6.63
   2 216.153.20.29
.. nothing else more than one..

The #2 on the list is doing things like this:

2013-04-29 08:50:54.110763 Connection timed out, disconnecting from 123.159.6.63:54137
2013-04-29 08:50:54.111417 Lost peer 123.159.6.63:54137 -
2013-04-29 08:50:54.111508     Connection was aborted locally, using
2013-04-29 08:50:54.111569     L{twisted.internet.interfaces.ITCPTransport.abortConnection}.

Are either of those two yours?