by todd vainisi.
Okay lookers, with special thanks to Howard and Ken who walked a mile in my shoes, I took care of this by upgrading my php to 5.5.
The installer said my php was adequate (I had 5.3.?), but I noticed in different thread (remarkably it was a thread where Ken was trying to get opcache installed on CentOS 5) that said that upgrading to 5.5 solves many ills.
After upgrading php, the installer immediately worked, all the way, and the other errors on first login disappeared too. I think Moodle should consider more strongly encouraging php 5.5.