Akonadi failure after MySQL upgrade to 5.1.42
There is a known bug with MySQL 5.1.42 that prohibits the QMYSQL driver from functioning properly. I finally found it on the MythTV bug tracker, which links it to the MySQL site. There is a patch available, but the bug was fixed in 5.1.43.
To fix it on my system, I grabbed the all of -current/source/ap/mysql except for the actual source, and downloaded the latest version (5.1.44) from mysql.com.
I hope this solves issues that others are having as well.