I started it back up with the previous channel list. It looks like it must be a problem with one of the channels that Dave tried to add. The error it logged was:

Sep 30 14:23:51 h1conlog2 conlog: ../conlog.cpp: 301: process_cac_messages: MySQL Exception: Error: Out of range value for column 'value' at row 1: Error code: 1264: SQLState: 22003: Exiting.

This would seem to imply that the value for one of the process variables was out of the range of the data type in the database. I'll try to narrow it down tomorrow.