I believe that my phals do indeed have the mystery disease.

Someone wrote to me offlist to say that he had had a similar problem
with his phals which turned out to be flat mites. He used something
called Safer (which I assume to be an insecticidal soap) and it took
care of the problem. I was excited when I read this and intended to
spray my plants tonight.

Then I went to the site Steve mentioned and which I also found via other
searching:
http://www.geocities.com/tlswilso/Ph...s_2-15-04.html

This has the most in-depth discussion of the problem that I've found
anywhere. Alas, it seems that flat mites are likely not the cause at
all. I'm thinking that I will try the soap anyway, but if it doesn't
help, I'm just going to bite the bullet and throw out my phals. (They
all have the problem). I'm just hoping it doesn't infect my paphs, oncs
and whatever others I have.

[sigh]
Norma

Steve wrote:

It resembles what I have been fighting in my Phal collection for 2
years. When I say fighting, I really mean watching it win. I made a web
site to show the problem to people in the hopes that someone knew how to
cure it:
http://www.geocities.com/tlswilso/Ph...s_2-15-04.html
..
..
..
This thing has turned out to be
quite a mystery and I hope you don't have that disease. Your pictures
lead me to believe you do.

Steve