need more details.
I have filled out your form a few times and got a few different errors ranging from Incorrect date time value: '12/2/2009' for column 'MDateOfEntry' to Data to long for column M1.
When you get the error "duplicate entry in database" it means you are trying to store a value that already exists in a column that has been set to not allow duplicates. most time it will happen if you are trying to set a value on the primary key column. review your database structure for columns that do not allow duplicates. Also double check the insert record behavior to make sure a value is not being set for the primary key column.