Mike,
probably some other user has updated/deleted the end of the PRIMARY index. Therefore this insert is blocked:
------- TRX HAS BEEN WAITING 12 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 0 page no 6768 n bits 128 index `PRIMARY` of table `zeiterfa/Zeiterfassung` trx id 0 13974162 lock_mode X insert intention waiting
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; 1-byte offs TRUE; info bits 0
0: len 9; hex 73757072656d756d00; asc supremum ;;
That insert is holding the auto-inc lock. The other trx is waiting for that auto-inc lock.
http://dev.mysql.com/doc/mysql/en/innodb-next-key-locking.html
Best regards,
Heikki
Oracle Corp./Innobase Oy
InnoDB - transactions, row level locking, and foreign keys for MySQL
InnoDB Hot Backup - a hot backup tool for InnoDB which also backs up MyISAM tables
http://www.innodb.com/order.php