Five of six miles from home I get a flat. Pull the rear wheel off and find that the tube is split. No problem, I've got a spare tube. Check the tire for damage and find none. Put the new tube in and in a moment of ecological guilt make the decision to use the new frame mounted pump (I'd normally use one of the two COs cartridges I carry - pump was purchased for those times 2 cartridges aren't enough). Everything is mounted and I begin to pump. First thing I notice is that the stem is flexing quite a bit no matter how much I try to steady things. Get the tire inflated and as I'm putting the valve stem cap back on I feel a slow leak of air. "Damn", I think; "I've broken the valve stem at the base again. This is something I've done before with a hand pump. So, I know I can't repair this and I don't have another tube. I walk home in cleats (although I did have cleat covers and it wasn't that bad). I get home and as I'm starting to take the valve cap off to replace the tube I discover that I forgot to screw the valve stem back down and that's where the air was coming from. Someday, if I'm very, very, very lucky, I'll be as smart as I think I am. In the meantime, I guess I deserved to walk.