...
#!/bin/bash
export NSPR_LOG_MODULES=imap:5;
export NSPR_LOG_FILE=/tmp/$LOGNAME.imap.log
/usr/lib/thunderbird/thunderbird &
Subscribing
After IMAP changes (including a cyrus reconstruct that fixed something), right click the account and choose "Subscribe ...".
References
Thunderbird as a Gmail client: http://kb.mozillazine.org/Gmail