Excel 2007 doesnt show Y-axis accurately when the values are small (eg. In
the order of -14th ~ -15th).

You can duplicate such behavior simply by creating a new document with two
fake data sets, one with the Y-values in the order of -15th, and another with
the Y-values in the order of -13th.

1st chart

X=1, 2, 3, 4
Y=1.00E-15, 2.00E-15, 3.00E-15, 4.00E-15

2nd chart

X=1, 2, 3, 4
Y=1.00E-13, 2.00E-13, 3.00E-13, 4.00E-13

Then, insert an XY scatter plot for each data set. You can see that the 1st
chart (with Y-values in the order of -15th) does not show any value for
Y-axis other than 0, while the second chart is showing values for major tick
marks. There seems to be some "cut" in the order of -14th ~ -15th.

Older versions of Excel that I have (2000 & 2003) do not display such
behavior. I have contacted Microsoft, but so far, no resolution (at least,
they confirmed that such behavior exists).

I was wondering if anyone here knows how to work around such problem. Any
input will be much appreciated.

Thank you.