One of my clients did the same thing and later it was fixed.
It can be problematic in many scenario and mysql server restart can be required. It leads to below errors and don't allow connections to mysql database.
110329 12:01:13 [Note] Slave SQL thread initialized, starting replication in log 'mysql-bin.003726' at position 850699172, relay log './poxxxx-relay-bin.000821' position: 11845356 110329 12:01:13 [Note] Slave I/O thread: connected to master 'firstname.lastname@example.org:3306', replication started in log 'mysql-bin.003726' at position 850699172
Too many connections