Karl Fogel at
If you're reasonably expert in GPG Agent, Debian GNU/Linux, other agent processes that might be interfering with my gpg-agent :-), and with passphrase caching in general, DM or email me. I'll pay your top consulting rate. I ain't got time to debug this all by my lonesome.
Subversion's passphase caching (and its interaction with gpg-agent) might be an issue here too -- I'm not sure exactly which of the many moving parts is the one causing the problem, so I can't say for sure yet.