Alex,
I notice the same thing with my Vixen GPD2 IF - and ONLY if - I lock the polar scope setting circle in place.Seeing I do NOT use the thing, I simply unscrew the screw and place it somewhere safe. Nothing will fall out. I replace the screw at the end of the night.
So,just remove the screw
In this day and age of GOTO, is the setting circles even needed, unless you go "old school"