Have you downloaded, installed and applied the V4 weight mapped version of the support files?

When you convert the clothing select V41 in the "from" and "to" lists.

In the conversion options include the option to Keep Existing Morphs and Add Full Body Morphs. Then follow the prompts as they appear.

A video tutorial is available at:-
http://www.philc.net/WW2_FBM.php

To the right of each panel in the convert window you'll see a button marked "?" clicking it will enable a pop up giving quick notes explaining what the adjacent GUI elements do.

Hope that helps.