I hit send before uploading the attachment and added it in a second post - the row_rsChild comes at line 12 but there was no recordset on the page... not sure if this is what I should be doing, but I copied the recordset (child) from the first page and pasted it onto the bindings panel on the second page. Now I've got a recordset on that page and the error still shows up but is now on line 48. I've attached the new version of the page.
Eric: I did some more work on my new page with the DD lists in place and got it to work, but then got a recurrence of the "duplicate" error message. I posted another message on what was happening with this new page on the DD forum and Dave Bucholz kindly pointed me in the right direction. I've solved that problem but am still getting an issue with the duplicate message occurring, which I've posted on again in the DD forum.