MySQL bin log missing data?

Question

I'm trying to make heads and tails of my binary logs and am coming up short. I have many entries similar to the following from mysqlbinlog but I'm missing log data that I know should be there.

# at 1050548
#130617 18:40:03 server id 1  end_log_pos 1050619   Query   thread_id=844988    exec_time=0 error_code=0
SET TIMESTAMP=1371519603/*!*/;
BEGIN
/*!*/;
# at 1050619
# at 1050782
#130617 18:40:03 server id 1  end_log_pos 1050809   Xid = 33121028
COMMIT/*!*/;

It's puzzling because I get expected SQL in the mysqlbinlog output for statements executed in phpmyadmin but those coming from other PHP-based remote web servers appear to not be recorded.

My settings bin logging are:

bin_log = /path_to_sql_incrementals
binlog_ignore_db = mysql

Am I missing a logging option?

Mysql 5.0.95 / CentOS 5.9