Problems with argument formula

Please see attached spreadsheet.

I am having trouble figuring out why the formula on the 'UCA Summary Data' tab for the "Definitized in FY10" chart does not work for the month of January. I am simply trying to count the number of items that were definitized this month, but it works for every othe month but January.

I also have another problem with the 'UCA Summary Data' tab. The formulas I have in the "Overage in FY10" and "Overage in FY11" charts seems to miss counting items that become overage at the beginning of each month or at the end of the fiscal year. Can anyone help me with either/both issues?

Blanks are seen as 0 and dates are numbers such that 0 on a 1900 Date System is 0 Jan 1900.
It follows that given you're testing only for the month (and not the year) these Jan 1900 values are included in your result.

To resolve either

a) add a further test to the SUMPRODUCT to account for blanks

=SUMPRODUCT(--ISNUMBER('Definitized UCAs'!$L$3:$L$6000),--(TEXT('Definitized UCAs'!$L$3:$L$6000,"mmm")=E16))

b) add year to the string

=SUMPRODUCT(--(TEXT('Definitized UCAs'!$L$3:$L$6000,"mmmyyyy")=E16&YEAR($A17)+1))