One annoying thing about the E-P2's design is the way the main dial on the back can be easily pressed and rotated while carrying the camera. I've already inadvertently changed aperture, ISO number and white balance. Sometimes I fail to notice it and I take a number of shots with the wrong settings. This is more of a problem with a pancake lens mounted, since then I have to hold the camera by the side grip and my thumb accidentally falls on the dial. With a larger lens I tend to carry the camera holding the lens barrel. That's where the center of gravity is located, even if the lens is not too long, because the camera body is so light. But even in this case I have accidentally changed some settings.
Changing subject, have you ever noticed how the "shadow" white balance setting works quite well on some open daylight shots, lending a pleasing warm light to the scene? I realized that... hmmm... accidentally.
Olympus E-P2 + Zeiss Sonnar 135/2.8 + extension tube