Dock randomly switches between screens. Any way to stop? I have a iMac running OS 10.9.3 that has 2 monitors connected to it.

Randomly, thourhgout the day the dock will flip either to the left or right screen. Its pretty annoying.

Does anyone know what is causing this or how to fix it?
Dock position could be changed when You place Your mouse on the bottom edge of the secondary screen and then move it down again.