I'm using a simple Countif in XL2003 so don't need to CSE it. It fights with
a named range and I cannot see why. It worked when I set it up, but the
moment I changed anything it stopped. Where am I going wrong?

Given a 50-cell range $B$20:$B$44 and $B$56:$B$80 named as F_Shell.
Formula =COUNTIF(F_Shell,"0").
This returns #VALUE, but it returns the correct number if I use the cell
references.
I've tried entering it as a CSE: no change.
I've tried the suggestion from other questions in this forum to ensure it is
not text format, but general + double-click + enter: no change.

I'd appreciate any pointers.