Is anyone else having issues with pinch to zoom? Three times now in two days this feature on my SP4 has randomly stopped working. Touch inputs for scrolling still function as they should but it will not zoom in or out with touch, which is very annoying. A reboot fixes the problem but it seems to come back once again after a while. My SP4 worked fine before bed last night and I go to use it this morning and pinch to zoom no longer works (it was plugged in all night). Any ideas how to correct this? Thanks in advance!