Difficulty looking up certain elements for list box

[Its Me]

Using SP1.

Simple data source schema:

myFields (group)
B (group)
b_to_a_ref (text field)
A (group)
name (text field)
a_to_a_ref (text field)
a_to_a1_ref
A1 (group)
name (text field)

Each <x>_to_a_ref (or <x>_to_a1_ref) is supposed to be a link to an A (or
A1) .

I want a drop down list for each <x>_ref field to show me ALL A's and A1's
in the current document. So for each a_ref I chose "Lookup values in the
forms data source" wiht an xpath of:
/my:myFields/my:A/my:name
and for the a1_ref I chose an xpath of:
/my:myFields/my:A/my:A1/my:a1name

But this only works for the b_to_a_ref field;. The a_to_a_ref field only
shows the name of the current A element, even if there are others. The
a_to_a1_ref field only shows A1 elements contained within the current A
element, even if there are other A1 elements within other A elements.

Am I doing something wrong?