This has become a complete mystery to myself and several bike shops in the area. It all started happening in March when all of a sudden every single morning I would come down stairs and find that my front wheel was flat. For the longest time we (which is the bike shops that I frequent and myself) thought somehow the tube was being pinched. It started to become a mission - every time the tube was replaced, whoever changed it would thoroughly check to make sure that wasn't the case. Tools were never used, etc..
Well, eventually I gave up and replaced the wheel itself, the tire and put a new tube on it. One month later, the exact same problem is happening on the brand new set up. I have had the change the tube every day this week and it makes no sense.
Since it may be asked, I'll tell you that the hole appears in different places. Sometimes it is on the inside of the tube, sometimes on the side or the outside (like I ran over something). They are never in the same spot on the wheel either. And, in all this time, my back tire has never gone flat.
So, does anyone have another theory as to what could be happening?