MySQL "The number of columns does not match the number of values", but the counter matches

MySQL throws this error when I try to execute a query when the number of columns matches. Here is the table structure:

mysql> desc S_3068; 
+-------------------+----------------------+------+-----+---------+-------+ 
| Field             | Type                 | Null | Key | Default | Extra | 
+-------------------+----------------------+------+-----+---------+-------+ 
| SfmID             | smallint(5) unsigned | NO   | PRI | 1       |       | 
| DatValue          | float                | NO   |     | 0       |       | 
| DatRawValue       | int(10) unsigned     | NO   |     | 0       |       | 
| DatTime           | int(10) unsigned     | NO   | PRI | 0       |       | 
| DatBusOrder       | tinyint(3) unsigned  | NO   | PRI | 1       |       | 
| DatFormulaVersion | tinyint(3) unsigned  | NO   |     | 0       |       | 
+-------------------+----------------------+------+-----+---------+-------+ 
6 rows in set (0.00 sec) 

I get the above error while executing this request:

mysql> insert ignore into S_3068 values (133, 15.82, 5542, 1339309260, 0, 1); 
ERROR 1136 (21S01): Column count doesn't match value count at row 1 

As you can see, the number of columns corresponds to the count of values. Now even more perplexing is that the query works fine with SfmID = 132:

mysql> insert ignore into S_3068 values (132, 15.82, 5542, 1339309260, 0, 1); 
Query OK, 1 row affected (0.00 sec) 

SfmID is unsigned smallint, which makes no sense to me.

Any help on this would be greatly appreciated.

EDIT: The error is caused by a trigger associated with the table. Please see Comments for more information.