mysql 5.1.70 with handlersocket hangs on SIGHUP

[slimlv]

mysqld 5.1.70 with handlersocket loaded and used for read-only operations hangs on SIGHUP signal - no future sql query executed, no clear shutdown of mysqld possible, stops on:
131101 17:44:50 [Note] /usr/sbin/mysqld: Normal shutdown
131101 17:44:50 [Note] Event Scheduler: Purging the queue. 0 events
131101 17:44:50 [Note] Slave I/O thread killed while reading event
131101 17:44:50 [Note] Slave I/O thread exiting, read up to log 'binlog.001390', position 96845380

mysqld may be killed with -9 only

[gds343]

mysqld may be killed with
ashraf osman