Hi -

As for as I know, ALL factories that produce ANY kind of chocolate also
produce milk chocolate.  Kosher facilities DO keep equipment separate, or
re-kosher between runs (I suspect the former) but ...
bear in mind that chocolate cannot be mixed with water during manufacture.
(Try melting chocolate and then adding water; you'll see that the results
are not ideal.)  This means that milk is added in powdered form.

And of course, if the milk is powdered, a trace amount will fly away from where
it's supposed to be, and land where it's not supposed to be.

This is why chocolate is such an iffy proposition for people with ultra-
sensitive milk allergies.

However, if you've been using a particular brand with no difficulty before,
then as long as they don't make significant changes to their factory,
you're probably ok to continue.

In the case of the Sam's chips, I suspect that you are seeing a change in
labelling only.  But do call to check if you're concerned.

--Beth Kevles
  [log in to unmask]
  http://web.mit.edu/kevles/www/nomilk.html -- a page for the milk-allergic