Counting Rows based on Month & Year

It seems something quite simple but i just can't get my formula to work. What i got so far is:

=COUNTIF(MASTER!c3:c999, DATE(YEAR(MASTER!c3:c999),MONTH(MASTER!c3:c999),1)=DATE(YEAR(B10),MONTH(B10),1))

what im trying to do is count how many rows contain the month x, and the year y (in this case i've entered the value 01/11/2006 in cell b10, and so should find out the number of rows in november 2006)

the c column on the master sheets contains various dates.

Unfortunatalty all i get returned from this forumla is 0.

What am i doing wrong?

Here's another option...

=SUMPRODUCT(--(TEXT(MASTER!C3:C999,"mmmyy")=TEXT(B10,"mmmyy")))