I went to the WinXP Control Panel "Regional and Language" dialog and in the "Customize" section of that there is a decimal point drop-down choice... was frustrated for a bit, because there seemed to be no other option than a point!
After some wall-banging I tried simply selecting and then replacing the point with a comma... voila!... all the error log messages about "colocated" vertices went away.
Now the error log simply says:
"Error in exporter: Mismatch between # vertices (272) and # normals (288 ) in part Pilot."
Okay... so, I added a Normal modifier to that part and checked "Unify" etc... no dice... now I'm back to twiddling an Optimize modifier and its spinners... (Jeez what a fight!)