Sliderendcircle substitution doesn't work on OS X build with custom skins. I have made a blank sliderendcircle.png file for my skin as well as try some other skins with blank slider end circles, however it still has them for me. I tried to confirm the issue with sending the skin to my friends and they reported back to me that they do not have the end circles with my skin, but I do.
I have no way to confirm whether the bug occurs with stable or cutting edge releases for me as current OS X build is locked to fallback release.
I have no way to confirm whether the bug occurs with stable or cutting edge releases for me as current OS X build is locked to fallback release.