Thanks for your reply. I will look into whether I could learn how to submit a CentOS package. Obviously, these Enterprise Linux distros often lag behind, for stability - but if people install the Yum package, they're definitely not getting the best version. If I can contribute, I will.
In the meantime, thanks for this mailing list - I'm learning my way around fail2ban, and have written a personal WordPress plugin that writes to a log file if a comment is marked as spam; the file is monitored by a jail I've created - the reason I haven't offered this to anyone yet is that I'm dreadful with regex patterns, and I seem to have some problems with fail2ban banning IPs after 1 failure, if I open and update the log file manually (when it scans, it bans every IP even if it's less than maxretry). Once I've been able to quantify the problem, I will post it here so people can have a look and hopefully help me solve the bugs.
But given that this is all running on an old version of fail2ban, that could be part of the reason I have problems :)