Attempting to start an OTR session with a recipient using Pidgin on Windows 7 and Gentoo:

Attempting to start a private OTR session with Joel Crisp (id-redacted)...   13:33:27
Error setting up private conversation: Malformed message received   13:33:28

I also see
    ?OTR Error:You sent me an unreadable encrypted message
in the chat logs.

I also see similar errors from Gibberbot on Android if I'm using Kopete. If I switch from Kopete to Pidgin, everything works, and Gibberbot stops complaining. So I'm taking the majority vote and initially guessing that there's a Kopete bug, though it's also possible that Pidgin is at fault.

Please let me know what I can do to try and help track down the problem.

Reproducible: Always

Steps to Reproduce:
1. Attempt to start OTR conversation with user who is using Pidgin.
2. Watch error messages crop up.
3.