If the definition of a dialog field define the field type, for example, as Boolean, and if the stored value (in the JCR repo) is of type String, the related dialog will not be displayed.
Current implementation do not guaranty the integrity of the data type.

Solution:
If a inconsistency is detected between the field definition and the stored type, give the authority to the definition:

• JCR stored type is String
• Definition is Boolean
  --> JCR data will be converted to a Boolean Type and value.

If the JCR value is not convertible to the definition type, null value is then used.