Help with custom functions

I have some custom functions in an excel spreadsheet that a couple people use for this particular template. I put these functions in the "Module" section. These functions work fine on my machine and another co-workers machine. We all use Excel 2003, but another co-worker, also on Excel 2003, will get the "#NAME" error whenever she tries to change the value of any of the cells that these functions use to calculate a value.

Function div(cell As Variant) As Variant
    If IsEmpty(cell) Then
        div = ""
    Else
        div = cell / Range("$B$9")
    End If
    
End Function

Function pst(x As Variant) As Variant
    If IsEmpty(x) Then
        pst = ""
    Else
        pst = x
    End If
End Function
Function ifx(cellx As String) As String
    If Left(cellx, 2) = "'X" Or Left(cellx, 1) = "X" Then
        ifx = 1
    Else
        ifx = "N/A"
    End If
    
End Function

Function lf(rate As Variant, load As Variant, hour As Variant) As Double
    Const LoadFactorA = 2.151814912
    Const LoadFactorB = 1.930413331
    Const LoadFactorC = 1.585907751
    Const LoadFactorD = 1.423288683
    Const LoadFactorE = 1.2394746
    Const LoadFactor0 = 0
    
    If rate = "" Then
        rate = 0
    End If
    
    If hour = "" Then
        hour = 0
    End If
    
    
    Select Case load
        Case "A": lf = rate * LoadFactorA
        Case "B": lf = rate * LoadFactorB
        Case "C": lf = rate * LoadFactorC
        Case "D": lf = rate * LoadFactorD
        Case "E": lf = rate * LoadFactorE
        Case "": lf = rate * LoadFactor0
    End Select
    
    If hour > 200 And lf = rate * LoadFactorA Or lf = rate * LoadFactorB Then
        lf = lf * 200
    Else
        lf = lf * hour
    End If

        
End Function
Function prod(cost As Variant, factor As Variant) As Variant
    Const FactorF = 1.09601428571429
    Const FactorG = 1.175
    Const Factor0 = 0
    
    If cost = "" Then
        cost = 0
    End If
    
    Select Case factor
        Case "F": prod = cost * FactorF
        Case "G": prod = cost * FactorG
        Case "": prod = cost * Factor0
    End Select
End Function
Function divide(x As Variant, y As Variant) As Variant
    If y = 0 Then
        divide = 0
    Else
        divide = x / y
    End If
End Function

I haven't the slightest clue as to why it'd do this especially since it works fine for myself and my co-worker.