Can't use the scrollbar on the map list, the server list, and in the control list.

Okay, so, i was trying the new snapshot, going on the server list to see how the arrows to change the order work, but when i try to use the scrollbar, it can of... jerk around. When i'm trying to scroll down, it goes up, and when i'm going down, it goes up! Well it's not doing it smoothly, it's going in the good way with some difficulties, then stop, and go in the other way... Well i don't know how to describe it... Let me make a video...