I've been testing some of my DAZ purchases (spanning from 2003 - 2010) and here's what I've found:

When I requested a download reset for the M3 Head Morphs and M3 Body Morphs, the new download I got for the Body Morphs was an updated installer, so it worked.  However, the new download I got for the Head Morphs was the same old installer from when I had originally purchased it, so that's why it won't work.

"You don't know what we can see
Why don't you tell your dreams to me
Fantasy will set you free." - Steppenwolf