Comment date formatting not working.

I noticed this when I originally installed 2.8.5, and it has persisted through my update this morning to 2.9. Quite simply, the comment date formatting doesn’t work and I can’t figure out why. I’m pretty much a WordPress noob, but it looks to me as though the mysql2date function is returning the literal date string instead of the translated date string. In other words, this is what I see as the datestamp for posted comments:

Username says:
%A %B %e%q, %Y at %I:%M %p

Interestingly, dates seem to work on posts. However, if I recall correctly, I had the same problem with times on posts, so I just removed the timestamp from the theme and left the date. No problem there. But removing the stamp from comments is proving not to be so simple. Any ideas?