I think the likely case is that the other computers have an older version of the template and that is why they can still open the forms. You probably have a newer version that has been modified in such a way that the documents won't open in it anymore.
That is my guess anyway.
Regarding my earlier question, when you look at the data source taskpane in InfoPath design mode, does myFields have a child node called LumbarRange? Is there no node with that name, or does it have a parent that's not myFields?