Paul, thanks, but I did save it as a dynamic PDF file. It still doesn't work.
Please note that I can make it work in Adobe Acrobat 9, but only with manual intervention. If I select Forms, Form data ..., Import data and select the XML file, I do get the complete data view with the repeating subform.
But Adobe Reader doesn't have any such command, and in fact I would prefer that the end user doesn't have to enter such commands anyway. I would much prefer that the PDF file automatically swallows the XML file from the same folder with a hard-coded name, exactly as it works in the LiveCycle Designer preview. But currently I can't make it work at all in Adobe Reader 8.1.3. If you ever had this work, which version of the Reader was that?