UPDATE: It appears that reinstalling CiviCRM resolved the problem, although we haven't completed a test import yet.
Strange that a reinstall on top of the existing install cleared the error, as Joomla reported a successful installation in both instances.

I'll post another update when I know more.
Chris
INTERESTING - One thing I just noticed: When I did the first install, I used civicrm-4.1.1-joomla-alt.zip because I was getting a zip functionality error. This time around, I used civicrm-4.1.1-joomla.zip (because I was able to resolve the zip error by upgrading PHP), without even thinking about it. You guys might want to double-check the alt file and make sure everything is cool there.