I dealt with this a while back when I still used TunerPro.
http://nefariousmotorsports.com/forum/index.php?topic=6356.0Unfortunately, I forgot the solution (haven't used TP in years), and the link I posted with the solution is gone. (end of the thread)
Basically once I edit an xdf, the next time I try to open it, says "names must start with an alphabetic character......."
Thanks, gents.
*edit Simply copy/paste-ing the maps from one TP instance into a blank xdf (in another instance) allows it to open correctly. Still interested in fixing the original issue if anyone knows.