Moving fields on an infopath form from an optional section to a new group...what are best practices

[Pack10]

I have an InfoPath form which I am testing with the users, they requested I move a field that was part of an optional section
and they want the field out of the optional section ...but If I move it I receive the following error: "Control bound to missing field or group"

In InfoPath, if I want to make a change like that, and if I add the new option buttons, they appear at the bottom of the data source.
Is that ok? Do I care if its on the bottom?

So, again I have an option button bound to an optional section but I need to move it to its own group. If I do that it appears at the bottom of
the data source, does that mean anything? I was trying to move it to its logical order but I was getting the error message above.