I am trying to configure a linked datasource in "Join" mode to be used in a Data View Web Part showing a kind of parent-child relationship. The data comes from two lists, and one of these lists has folders - more specifically, the folders have a custom content type which is, in turn, derived from the stock "Folder" content type.
The problem: the linked datasource retrieves only the top-level folder entries from said list (I've verified this by comparing the values of the ID field returned by the data source with the IDs of those folder items), and does not return any data items inside the folders regardless of what I choose in the "Item and folder scope" drop-down.
Target environment: MOSS 2007, SharePoint Designer 2007 SP1
Would be grateful for any hints, if this is at all a supported scenario.
Thanks in advance!