It is making me INSANE that I have to use the arrow keys to move the viewpoint because the mouse will freely move right over onto my second monitor even though there's no game being displayed over there.  Every other game I play, the 2nd monitor becomes locked off and I have to alt-tab to interact with anything over there.  This functionality is really weird and makes moving around a pain in the ass.

I'm also having this issue, and have done the same thing you are doing to fix it. Beyond disabling the second montior view entirely I haven't found any other workarounds.

 

This should probably be moved to the bug forum if there isn't already one there.

Edited August 20, 201411 yr by Azureblaze

depending on what basic toolkit they are using for development, there should be a flag for the window object that locks the cursor to only move within the window. 

I concur that doing this for both fullscreen and window is a good idea, alt-tab to break the lock works good enough when you want to move the cursor out of the window/to another monitor.