The way you put it, you basically only want to count the non-blank
cells of 2nd col. If so, a generic solution involving SUMPRODUCT (and
not using one of the COUNTx functions):
=SUMPRODUCT(--(B1:B10<>""))
If you want a COUNTIF on A:A (e.g. all the 5's where B:B is not blank,
=SUMPRODUCT((A1:A10=5)*(B1:B10<>""))
Note: the -- in the first formula is to convert the TRUE/FALSE that
the expression produces into 1/0 so that they can be summed (logical
values are ignored by aggregate functions). In the second case
multiplication does the conversion thus the -- is not needed.
HTH
Kostis Vezerides
HTH