MS Excel / VBA help thread

Hmmm. I decided to change one named range to OFFSET to try and highlight the problem.

Here is my conundrum:
CONF ='Jan11-Apr15 Cases'!$F:$F

Here is the formula i use it in:
=COUNTIFS(Infection,'DM NA calculations 2015'!R21,CONF,"Suspected")
This returns a number I expect.

when i create CONF2 =OFFSET('Jan11-Apr15 Cases'!$F$1,0,0,COUNTA('Jan11-Apr15 Cases'!$F:$F),1)
and use it in
=COUNTIFS(Infection,'DM NA calculations 2015'!R21,CONF2,"Suspected")

I get #VALUE!

Is it because there are blanks in the range?
I've tried using (from http://www.ozgrid.com/Excel/DynamicRanges.htm)
4:Expand Down To The Last Text Entry

In The Refers To Box Type: =OFFSET($A$1,0,0,MATCH("*",$A:$A,-1),1)

And that no work either.