This morning I noticed that one of my new tires had lost quite a bit of air so I had to trek over to Discount Tires to have it checked. It turned out that it was the valve stem that was leaking. They tightened it and put some sealant on it. I hope that will do the trick. I'm thankful that it wasn't more serious. It was just an annoying side issue. Even for short trips like that, I still have to "batten down the hatches" just as I would for a longer trip.