This problem is still being looked at currently. I believe it has to do with the fact that the Numeric Edit control is built out of multiple sub windows. It may be that one of those sub windows holds the focus. In this case it would return the Resource ID of the sub window, instead of the Numeric Edit control's resource ID. Unfortunately, the only work around may be to hardcode situations where you want to get the Resource ID of the NumericEdit control. I will keep you updated on any progress with this issue.
Regards,
Tyler Tigue
Applications Engineer
National Instruments