Now, I first noticed this problem while checking e-mail via the web, but I eventually found that if I hit my site for much of anything, it would trigger the block. Eventually the Cisco flakes enough that it resets itself, and I'm able to get back to my server. But I have to step carefully, and blogging seemed to be another trigger.
Well, that made blogging regularly difficult. My already atrophying blog got worse. Time at night has been hard to come by, and I'm not all that good at queueing up my thoughts during the day. Luckily, I've found some software that will connect to my server and just post an entry. I'll have to see if this triggers the block, but for now, it's a start. Such are the trials of running your own server.