I've seen two kinds of mighty mice ... one kind has white 'squeeze' buttons on the side (which are used with exposé by default) and the other kind has grey ones. What's the difference between these two types of mice except for the color? Is it just me, or is the one with the white sides easier to perform a right click? I just couldn't do it with my old MM (grey sides) and now my dad got one (white sides) and I can right click perfectly. Any idea?