It happens even with an out of the box fresh krpano package, running outside the browser. Sometimes everything is OK, sometimes it just helplessly keeps zooming out ... 
I drag to look around a pano, release the mouse and then the view zooms out ... 
I just click on the pano, and it will zoom out the same way ... 
This problem has been driving me crazy for over a couple years already ... It is very random, I believe it is NOT krpano bug. In fact I am pretty sure it is a problem with the computer used to view the app ... I've tried different settings, browsers, computers ... in the end I just decided to lock the fov on my krpano applications ... 
Has anyone ever encountered this problem 