Photoshop: Switching documents while running an action causes the action to run on the wrong document

When you start an action and switch to the next file with ALT+TAB, the action runs over the new image and not in the original file. So you can ́t start a (i.e. long) action and work on other files...

Btw: After canceling the action there is no way to stop it completely (in Button Mode). Why???