Can't apply NAMES to pre-existing formulas

Hi there,

I have defined NAMES for some cell ranges.
These work well when I type in new cell formulas (the range I type in automatically gets replaced by the corresponding NAME), but I can't use the NAME>APPLY to replace cell references in existing formulas. I get the following error message:
"Microsoft Excel cannot find any references to replace"
even though the reference is there indeed, and the name is highlighted in the apply box.
The cell by the way include several ranges BTW.

What am I doing wrong?
thx,
jm

I forgot to mention: the NAME refer to ranges on another spreadsheet