Hello,
I am having the same issue as this: http://wp-types.com/forums/topic/types-image-field-how-to-delete-image/
BUT now the image cannot be deleted or modified at all. Once you save a post its in, may not be changed, overritten or deleted.
Also removing the content of the image field by hand and leaving an empty box does nothing.
Such behavior makes it unusable. 
Can anyone help ?
Cheers,
Junta