I'm going insane

I'm trying to compare two sheets using Walkenbach's approach but for
some reason when I use it...certain values don't show differences.

Example:

Sheet 1 (Range Name is Grid) has 18000 on Cell A1
Sheet 2 (Range Name is OldGrid) has 18000 on Cell A2

So if I change Cell A1 on Sheet 1 to 1 it should show me change but
no...it just does nothing. However if I type 133...it shows change.

Selection.FormatConditions.Add Type:=xlExpression, Formula1:= _
"=COUNTIF(OldGrid,A1)=0"
Selection.FormatConditions(1).Interior.ColorIndex = 40

Help really appreciated...


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wayliff
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