Bug#697597: [debian-mysql] Bug#697597: mysql-server-5.5: COMMIT has an effect on MyISAM tables

[Steven Ayre]

This sounds like a metadata lock being held until the COMMIT.

Perhaps the same as MySQL bug 61391?
'Metadata lock held on MyISAM table when AUTOCOMMIT turned off'
http://bugs.mysql.com/bug.php?id=61391