Firstly, I apologise if you have not been contacted, I have always read your posts and can clearly understand that you are very knowledgeable and very passionate about monochrome, so we share that outlook, I can assure you the next time I am in the USA I will visit with you.
As to 'black spot' I am sure you can imagine I was concerned at your assumptions. This morning I have spoken to our QC department and obtained the worldwide statistics relating to PAN F + ( 35mm and 120 )
We have received :
2011 Year to date 1 Complaint
2010 1 Complaint
2009 4 Complaints
2008 2 Complaints
So in the last 3 years and 8 months of sales worldwide you can see that we have had 8 complaints :
Of those 8 complaints 5 Were Justified
1 Cause not certain
2 Not justified
I cannot therefore, respectfully agree that PAN F + has a problem. As to this customers issue he is returning a sample to us and once it is examined under the electron microscope by our QC team we will give him ( as we give all our customers ) an official reply.
'Black Spot' as I am sure you realise is a problem sometimes seen in 'home processing' due to suspended particulates in the developer, either from the mixing water or from undissolved or 'foreign' particulates in the actual raw chemicals, it tends to be much more common when powder developers are used.
Finally, your assumption that it could be caused by moisture actually on the film or on the backing strip I cannot really comment on other than :
1) Film that is cool strored or frozen must be protected from moisture.
2) Once film is exposed it should be processed quickly and not put back into cold store ( unless in exceptional circumstances and again protected from moisture ).
3) If moisture was introduced to a film ( or via the backing paper onto 120 film ) I would not expect to see 'black spot' or pinpricks I would expect to see a fairly 'random' mottle effect after development that I cannot see would would induce multiple pinpricks in the emulsion.
Simon ILFORD photo / HARMAN technology Limited :