I did not discover what is deleting the registry key.
( I think it is firefox )
However, I made some changes to firefox that has kept flash functioning.
Read the last few posts at Mozilla here about my fix.
http://support.mozilla.org/en-US/questions/931884?page=2#answer-354190
I believe that mozilla was not willing to admit thier browser is deleting it's own registry keys.
They did provide information to keep flash functioning.
