Set 'include headers' in export spec, but does not save..

[don]

I'm trying to save an export spec where I've checked box 'Include headers',
then click 'SAve As' and overlay existing named (also tried creating new).

When I run macro using either newly named or same (or manually go back into
that spec), the 'Include headers' checkbox is always unchecked again.

How can I make it stick??

Thanks!
Don