Field for plugin showing up with "Geen titel"

I’m using the plugin with gravity forms and everything works fine with the only exception of the iDeal form field.
I cannot change the name label of this field or hide it in any way.
All i have is the field label just above the buy button with the words “Geen titel”
Any suggestions how to get rid of this.

You can see the form page via the following link:
http://www.hetluntersebuurtbos.nl/boek-verkoop/

Thanks

http://wordpress.org/extend/plugins/pronamic-ideal/