[OS X Emacs] Aquamacs kill word problem

[Robert Goldman]

I am finding that when I do aquamacs kill word in at least some latex
buffers, it kills to end of line instead of killing the next word.

I do /not/ see this behavior running aquamacs without customizations.

I believe that the problem is due to the fact that without
customizations the variable  minibuffer-completing-file-name is nil.

But in Auctex mode, I find that minibuffer-completing-file-name on *my*
customized Aquamacs is bound to 'lambda.

I'm at a loss to see how this could have been set, and find + grep isn't
making an answer jump out at me.

Anyone have any suggestions for tracking this down?

thanks!
R