I was curious if any other Zone Alarm 6.5 and Eudora users have experienced this.
Yesterday, I updated my Zonealarm Pro Firewall to Version 6.5. Shortly thereafter, I began getting warnings from Eudora that various mailboxes had out-of-date tables of contents, and did I want to rebuild?
This seemed to be happening every time I started Eudora. I took a look at my Eudora data directory, and noted that, indeed, the .toc files were never being updated as the .mbx files changed.
Since the only thing that had changed on my system was Zone Alarm, I backed out to Version 6.1. Problem solved. I re-installed 6.5 - problem back. Re-installed 6.1 - fixed again. Clearly, then, the problem is Zonealarm 6.5.
Potentially confounding factors are that I use avast! free to scan my email (though I experimented with turning that off) and store my Eudora data directory on a PGP disk. I also turned off the "Mailsafe" option in Zonealarm, which did not help.