I'm getting an error with a really nice description: Error The website encountered an unexpected error. Please try again later. Error message PDOException: S

I'm getting an error with a really nice description: Error The website encountered an unexpected error. Please try again later. Error message PDOException: SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction: DELETE FROM {semaphore} WHERE (name = :db_condition_placeholder_0) AND (value = :db_condition_placeholder_1) AND (expire <= :db_condition_placeholder_2) ; Array ( [:db_condition_placeholder_0] => variable_init [:db_condition_placeholder_1] => 203428328950f00b0bbd0484.53523159 [:db_condition_placeholder_2] => 1357908748.7708 ) in lock_may_be_available() (line 181 of /export/content/data/dlc/shared/www/developer/includes/lock.inc).