I am working on a Sitecore 6.5 (Update 5) solution. I have placeholders in some folders hierarchy (just to separate them based on functionality), all the content and presentation controls works fine with this placeholder folders, except WFFM.
I am using WFFM 2.3 for forms, when I try to assign the placeholders, the settings is not saved. If I use the placeholder from "Placeholder Settings" (root) folder then those placeholders are save correctly. How can I add the placeholders form the folder? I have attached screen shoot to show the folder structure.
In the image, content is selected from root, but other placeholders are not saved.
This seems to be a bug in the WFFM module. There is a Sitecore Query for returning all allowed placeholders and this query does only return placeholders which are a direct childs of the Placeholder Settings
item and does not search recursively for valid placeholders.
I suggest to create a Sitecore ticket under http://support.sitecore.net and hope for a hotfix.