Chart axis doesn't print date correctly

[eddyq]

I'm using excel 2003. I have a chart. Column A of the spreadsheet is the date. I have selected the Date format as 04/21/11. The dates are all correct and range from 9/11/09 to 4/20/11. But the X axis of my chart displays starting with Jan 0, 1900. One hint is that I have headings for column A that are not dates ... but the X Values in each Series starts with A6 which eliminates the heading rows. When laying the mouse pointer on the beginning and ending of the charted lines I can see the dates and they are correct.

Does anyone know what I could be doing wrong?