Word Macro not changing data

I have a series of marco statements that do similar things as the example code below. Sometimes, the macros will cycle through and not change things in the document. Most all the statements do what they are supposed to, but one statement will not. It is not the same statement each time either. Is there something missing in the sample code that would cause it not to do what it should? FYI: This code looks for March dd,yyyy and replaces with March dd, yyyy

Sample Code:

With Selection.Find .Text = "(March[ ^13][0-9]{1,2},)([0-9]{4})"
.Replacement.Text = "\1 \2"
.Forward = True
.wrap = wdFindContinue
.Format = False
.MatchCase = False
.MatchWholeWord = False
.MatchWildcards = True
.MatchSoundsLike = False
.MatchAllWordForms = False
End With
Selection.Find.Execute Replace:=wdReplaceAll