I had previously tried to get a user control wrapper datatype to transfer, and looked briefly into creating a custom provider.

However i realised that what i was doing with the custom datatype can easily be done with the built in xpathdropdownlist datattype - i figured that would solve my courier problem.

Unfortunately, the property data STILL does not transfer.

Using...

Umbraco 4.9.1

Courier 2.7.1

I have this set in my config:

    <contentPickers>
      <!-- add new datatype elements for data types that stores page ids (ex: "1242" or "1726,2362,2323") -->
      <add key="contentPicker">158aa029-24ed-4948-939e-c3da209e5fba</add>
      <add key="ultimatePicker">cdbf0b5d-5cb2-445f-bc12-fcaaec07cf2c</add>
      <add key="Ucomponents-XpathCheckboxlist">d2d46927-f4f8-4b1b-add7-661cc09a0539</add>
      <add key="Ucomponents-XpathDropdownlist">57a62843-c488-4c29-8125-52f51873613e</add>
      <add key="Ucomponents-AutoComplete">31aa0d5c-f8e1-4cdc-a66e-c7f8c09498ef</add>
      <add key="Ucomponents-MNTP-CSV">c2d6894b-e788-4425-bcf2-308568e3d38b</add>
      <add key="umbraco-user-control-wrapper">d15e1281-e456-4b24-aa86-1dda3e4299d5</add>
      <add key="XpathDropdownlist">173a96ae-00ed-4a7c-9f76-4b53d4a0a1b9</add>
    </contentPickers>

Any help would be greatly appreciated!