[TYPO3-mvc] Need help with mapping a "foreign" table

[Sebastian Michaelsen]

Hey,

I have an existing Non-Extbase Table for which I created a model class. 
But when I fetch an instance with $query all properties are set to NULL.

Here's my TS:

config.tx_extbase.persistence.classes {
	Tx_MyExt_Domain_Model_MyModel {
		mapping {
			tableName = tx_otherext_table
			columns{
				title.mapOnProperty = title
				# other properties...
			}
		}
	}
}

The Model extends Tx_Extbase_DomainObject_AbstractEntity and has a 
protected property $title with a getter and a setter.

What have I missed?

Kind regards,
Sebastian