Not long after getting my M10-P Safari, I found that the shutter release occasionally would fail to actuate the shutter. This mostly happened when shooting in the vertical orientation, however, it eventually spread to the horizontal orientation as well.
After a little fiddling around I realised that the shutter release button was loose! Simply tightening the collar that surrounds the button resolved the problem. The camera fires every time now.
By the way, the shutter button is easily removable. It’s a simple mechanical push button assembly that is screwed in. If you spill coffee or beer on your camera you can remove the button and clean it with contact cleaner or isopropyl alcohol. Once removed the shutter button can be cleaned without worry about damaging the camera electronics!