I will certainly change the tube in the morning and look for a shard of some sort. I just did not know if the valve stem meant squat or not. I have both tubes that went flat sitting in my garage pumped up and they are not going flat ( 3 days on the oldest tube) and its this phenomenon thats has me scratching my head. The tubes fatten every 2 days in the tire but are fine three days pst removal from the tire.