Flashing - always mean disease?
 

In the absence of any other symptoms, is flashing always a sign of disease?
I have one fish I just noticed doing it once or twice.

It doesn't ALWAYS mean an illness, on occasion I'll see one of my fish do a flicker or two. I would assume that like us, every once in awhile they get an itch. Is this a fish that is/was in the tank with your Mollys that had ich?? I can't recall if you isloated and treated the Mollys for ich, or if you treated the entire tank. Once one fish is exposed to Ich the entire tank has been exposed, and therefore, the entire tank needs to be treated. I can't recall reading what you did, but I do remember Abbey's great "Hospital Sign". :-D

Yes same main tank...but, I determined that the mollies suffered from a fungus. I put them in the hospital tank with Jungle Fungus clear and they were all cleared up by the next day - 3 days later I put them back in the main tank and the white areas reappeared in 24hrs. They are back in fresh hospital tank and will see treatment much longer this time.
I don't see any signs of ick on other fish and otherwise, this Platy is a horse....or a pig and seems really healthy. I am also noticing the Platys are favoring a far corner, musch as they did when the female mollies were removed the first time - I think the male molly is just a pita for all of them!