Strange chart problem - Y axis scaling

Hi all!

Ok I'm generally pretty good with excel but this one has me stumped! I have two charts each with two series. The lowest datapoint on the first chart is 280, and on the second it's 353. The strange thing is, altho they are both set to fully automatic scaling of the Y axis the first graph looks right and the axis crosses at 250, the second graph crosses at 0!

I've attached a sample spreadsheet to show what I mean. Does anyone know why this might be happening and if there's a way to have the min value on the Y axis of the second graph cross at a more sensible place without having to set the options manually?

~Shiv
(Excel 2003 SP2)