How to Fix a 45w Magsafe PS

I have been using a MBA for a little over a year and the power supply has been a bit cranky----it wouldn't always charge the unit. I would try different receptacles and after a period of time it would suddenly work again! I recently found out the reason why and I don't know if it is universal, but if the power supply is too cold it won't work. If the power supply won't work I hold it over a light bulb until it feels warm to the touch and voila it works!

Or just have Apple give you a new one. They have been very prone to failure.