I just upgraded to Windows 8.1 and now window snapping is pretty strange. It worked fine in Windows 8 for months but with Windows 8.1 it's pretty broken.
Mouse cursor drags off the top of the window being dragged when it hits the top of another window. Strange behavior in general while dragging. Too strange, in fact, to use it. I've turned OFF all window snapping and will leave it off until I hear of a fix or a new version shows up.
I know you've already put this on the fix list but I just wanted to report I too have noticed this. Specifically I notice the issue occurs when a window snaps to any side of another app window and if the mouse is moving in a diagonal motion, it trails off in the axis opposite of the snap angle.
That is, if the two windows are snapping on the Y axis (left/right side) and the mouse moves diagonally, it trails off in direction of movement on the X axis.
Just wanted to add that detail in case it helped.
For the user who disabled snapping entirely due to the issue, I thought about doing the same but I simply changed the option to only enable snapping with a hotkey being held down so I can move my windows normally and then simply enable snapping when I want it.
We don't have it planned for a specific version at the moment, so unfortunately I can't offer an ETA. If anything changes, we'll definitely post an update.
@Thosj: We've just released a new DisplayFusion beta version and the issue where the mouse cursor moves off the top of the window should be all fixed up. Please let us know if you run into any trouble after updating.