I'm trying to create a column chart out of data that looks like this:

x-axis y-axis
1/3/06 300
1/9/06 600
1/31/06 250
2/23/06 1000
3/12/06 50
3/22/06 450

....and so on. The number of data points per month varies. I'm using 1-Month
units in the scale of my x-axis, so my Jan. column should read 1150, Feb.
should be 1000, Mar. should be 500, etc. Problem is, Excel omits some of the
data points, so the Jan. column says 900, and Mar. says 50. But on some other
months, it counts all the data points in the month and shows the correct
total for the month.

I've tried column, stacked column, line, and XY charts, but the data points
remain missing. I've rechecked my numbers, dates, cell formats, also to no
avail.

I hope you can help. Thanks.