PDOException: Syntax error or access violation: 1305 SAVEPOINT savepoint_1 does not exist

I am getting this error with 7.15. They are consistently happening in pairs. I'm using mysql. Note this is

php

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1305 SAVEPOINT savepoint_1 does not exist: ROLLBACK TO SAVEPOINT savepoint_1; Array ( ) in file_usage_add() (line 661 of /var/www/website.com/includes/file.inc).

node

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1305 SAVEPOINT savepoint_1 does not exist: ROLLBACK TO SAVEPOINT savepoint_1; Array ( ) in file_usage_add() (line 661 of /var/www/buyagainbaby.com/includes/file.inc).

I originally posted about this in a related thread http://drupal.org/comment/edit/6556106.