Mysql not writing to binlog
From the 5.5 manual:


  Setting this option causes the log_bin system variable to be set to ON (or 1), and not to the base name. This is a known issue; see Bug #19614 for more information. 


Newer versions have made changes in this area, but there continues to be a difference between how the VARIABLE log_bin (in my.cnf) and the commandline --log-bin (when invoking mysqld).

From https://dev.mysql.com/doc/refman/5.5/en/replication-features-triggers.html :


  With statement-based replication, triggers executed on the master also execute on the slave. With row-based replication, triggers executed on the master do not execute on the slave. Instead, the row changes on the master resulting from trigger execution are replicated and applied on the slave.