Output File missing groups

[Matt]

I'm building an InfoPath form that will generate an XML output file, to be
used by another process. That process needs to see all the XML nodes, even if
there are no values in them.

In my schema, I have several repeating groups. If I fill in the InfoPath
form , but put no values into a repeating group, the XML output file doesn't
show that group.

Is there any way to force InfoPath to include all groups, even the empty ones?

Thanks,
Matt