Auto hide and vertical slider can cause volume to be turned up
I tried using the volume control in mini mode and while holding the mouse button down to adjust the vertical slider the bottom bar in the play hides automatically causing the slider to be pulled down causing the volume to be turned up bespite me not moving the cursor up.
It seems i can't get the controls to auto hide consistently so i can't say exactly what have to be done. But seems like you have to click the speaker icon to show the volume slider and move the cursor away from the controls and then (sometimes) efter 5 seconds the controls auto hide (slide down).