80mm ED Orions suffering from pinched optics?

On a couple of occassions I've seen pinched optics
in this scope. The diffraction rings are deformed
and the diffraction disc is triagular. This happens
when the temp. drops to around freezing or lower.
One person also noticed this on the ED apo yahoo
group. IMO, it's probably due to the aluminum cell
diameter being too close to the diameter of the
lens elements, and when it contracts due to the cold
the elements are pressured. While this doesn't effect
the image quality of planets, etc, very much (mild
astigmatism usually doesn't) it is a bit of a problem
with double stars. I figure I'll contact Orion to see
if any other cases of this have cropped up and if they've
determined it's due to the cell or something else.
It could be internal strain the glass, but I doubt it.
Owners of Orion, Celestron or Skywatcher versions of
this scope should look for it when the temp. drops.