I posted with the problem with silane caoted slides.  I'd like to thank
everyone for their wonderful ideas and suggestions.  As I look back at my
procedure it appears my slides have been sitting on a magnetic piece of
black metal when they dry!!!  We have limited labtop space so our scope
and histology area is actually an old desk that has a light colored top.
We have been using the black metal plate as a contrast background.  I have
just now thrown the metal piece out.  I am hopeful that this has solved
the problem, but I have also dipped my slides longer in silane.
Thanks everyone again for your help-Kathy