Caused a Slow Punture (15th November 2012)
Took the rear wheel out and the tyre off to check for spokes poking through after truing the wheel. All looked good.
Sadly I noticed the pressure had gone the next morning, when I wanted to ride it to work. This made me just about 1 hour late.
Probably caused by pinching the inner tube with the tyre as I faught it back onto the old steel rims.
My local bicycle shop, Hadron Cycles, charge £12 for a puncture repair with replacement inner tube. Annoying that I caused the puncture myself but at least the mistake is fairly cheap. Would soon add up if I did it often, though!