what is happening to you is very strange; I have the same
version of the Flash Plugin and it is working fine for me.
We are going to release an updated version of Shiny Groove (with
some fixes for Yosemite and retina displays) in a couple of days.
At the moment it has some rough edges and maybe some bugs. If you
want to - you can try this new version of Shiny Groove to see if
your problem persists and we will need to investigate it