Cursor getting locked in WoW window

Hey,

Does anyone know a fix for the problem when the cursor is getting locked to the WoW window?
In later clients there is a setting for this but i cant find it in 3.3.5a.
Now i cant move my mouse cursor to my second monitor. This only happends here. Works fine otherwise.

Thanks in advance

In video settings are you playing in fullscreen instead of windowed borderless?

Im playing fullscreen, tried windowed modes but it doesnt work. Would playing in windowed mode be the solution to my problem and i have to find a solution to why it doesnt run in windowed mode?