The issue is an odd one: Visitors leave comments. The comments subsequently disappear.
I know this because I get an e-mail every time someone leaves a comment. Over the last few days, I've noticed an increase in the number of "I thought I already posted this..." type comments.
Clearly something's wonky. Clearly I need to descend into the depths of Blogger geekitude to figure it out. For now, I'll repost comments from e-mail - not the most elegant solution, but at least your words won't end up in oblivion. Thank you for your patience while I work this through and move toward a permanent solution.
Your turn: If you also use the Google/Blogger platform and have noticed something similar, I'm all ears.