mod_pubsub_odbc disconnecting clients after node configuration requests

I've set up the crash log at https://gist.github.com/54a0f1788223b057ed33.

I have ejabberd set up to run mod_pubsub_odbc with no plugins and no additional settings. My reading of the logs suggests that the configure change indeed goes through, but ejabberd promptly disconnects the client before the response IQ gets sent (line 316). I'm having a hard time figuring out how the disconnect takes place. Any help would be appreciated.

Using just mod_pubsub without ODBC seems to go without issue, for what it's worth.

Thanks!