For some time now I've had the problem that every now and then, clicking the start menu button brought up the Win8.1 start screen, rather than the start menu provided by startisback. Today I've finally managed to track down what causes this - it seems that when the charms bar is invoked on the desktop, it activates the built-in start menu in Windows 8.1. This can be reproduced by doing the following: Click the Start Menu button, then in the menu select the "Connect to" option which will bring up the connectivity charms. Now click the start menu button again (you need to hit the lower left corner of the screen) You'll notice a different button background and the button is slightly larger (because the native button just is like that) and then instead of bringing up the start menu, it goes to the start screen. Click anywhere else after the charms bar has disappeared, and things are fine. Of course I have the lower left hot corner disabled, but it also happens if all hot corners are disabled. This happens even on the latest 1.5.1 version as well as previous versions.