CUBASE 8 PRO and Mouse Problems

Very strange mouse behavior,
I have Mac Pro 3.1 with Mavericks 10.9 and freshly installed Cubase Pro 8.
When I click on the mixer faders or EQ or any other button in Chanel Strip I cannot move it up or down with regular mouse movement click only if I press and hold “Option” key I can move the faders up or down.
It`s very annoying.
What is going on and how can I fix this?