VB: UDF - FUNCTION Instability

[Davexx]

hi, i have 2 or 3 user defined functions that seem to come up with errors intermittently. (for me, i noticed that on making any change to a function called either: ZOR() or ZAND() the error would come up right away / upon calculating a row). thanks in advance.


i can use help with:
- fixing the intermittent errors that popup on the top 2 examples
- making the ISTRUE function to work with a range of cells, eg: A9:C9

----------

the vb used to calculate row:

ActiveCell.EntireRow.Calculate

i have been forced to use vb for a manual type: hit enter on cell:

Cells(ActiveCell.row, "R:R").Formula = Cells(ActiveCell.row, "R:R").Formula

i am using winxp pro & excel 2002, upgrade pending but not right now.

ANSWER CHECK:
NOTE: at bottom i have a sample of a code that is stable (QLINK). if reason for stability, the code is divided into 2 parts (as below): the udf & then the rest of the code under area that activates code upon user click:
Private Sub Worksheet_SelectionChange(ByVal Target As RANGE) 'single click


ERRORS:
i am novice at vb & may need a working example / help with discovering what the problem is with this.
i have a couple of samples for udf's that are causing ERRORS:


'GETS NAME ERROR, HIT ENTER ON CELL TO FIX: (note: eg for range of cells possible)

Function ZOR(ParamArray Refs()) As Boolean    'find zero in OR(cells as:  =IF(ZOR(B9),1,0)  or  =IF(ZOR(B9:D9),1,0)
  Dim i As Integer
  Dim c As RANGE
  On Error Resume Next    'ON ERROR
  For i = LBound(Refs) To UBound(Refs)
    For Each c In Refs(i).Cells
      If Not IsEmpty(c.Value) And c.Value = 0 Then    'ZOR requirements:
        ZOR = True
        Exit Function
      End If
    On Error GoTo 0      'ON ERROR
    Next
  Next
  'ZOR = False  'not for OR, used in AND
End Function

'GETS NAME ERROR, HIT ENTER ON CELL TO FIX: (note: need help with test range of cells)

Function IsTrue(ByRef x As RANGE) As Boolean   'call as:  IF(ISTRUE(A1),1,0), not ready for a range of cells eg:  A1:B1
    IsTrue = False        'used to simulate test cell:  if isnumber & if >0,  need help making enter range of cells possible
    If x.Value > 0 Then IsTrue = True
    If Not IsNumeric(x.Value) Then IsTrue = False
End Function

'========== SAMPLE THAT IS STABLE: QLINK: used as alternative to hyperlink using: SCROLLROW, no more offsets.
'code in a module:

Function QLINK(rngToSel As RANGE, strFriendlyText As String) 'add to a module,  see sheet1 qlink
    QLINK = strFriendlyText
End Function    'for:  =QLINK($A$200,"A")  or  =QLINK($AD$200:$AF$200,"Friendly Name")

and the 2nd part within the sheet:

option explicit
Private Sub Worksheet_SelectionChange(ByVal Target As RANGE)  'single click


With Target     'end with at bottom 
    If .Count > 1 Then 'Exit Sub
      Application.EnableEvents = True           'EVENTS
      Exit Sub
    End If


    Dim strFormula As String, strRefToSel As String   'QLINK  quick link:  single click scroll row to destination for top of view, moving up -or- dn.
    Dim rngToSel As RANGE                             'part of Q LINKXYZ below
    On Error Resume Next
    strFormula = Target.Formula
    
    
    If UCase(Left(strFormula, 6)) = UCase("=QLINK") Then   'call as:  =QLink($A$897,"friendly name")
    'Application.ScreenUpdating = False             'no longer need update off
        strRefToSel = Mid(strFormula, 8)
        strRefToSel = Left(strRefToSel, InStr(strRefToSel, ",") - 1)
        Set rngToSel = RANGE(strRefToSel)      'remove:  Me.  to keep from selecting destination up front & get rid of update off.
        'Set rngToSel = Me.RANGE(strRefToSel)  'orig      'Application.DoubleClick    'no longer need
        
        If Not rngToSel Is Nothing Then         'jump to rng & do scrolling 
            ActiveWindow.ScrollRow = rngToSel.row - 1     '<< SCROLL  yes
        End If
        

    Application.Goto rngToSel   
    End If


end with
end sub

i can use help with:
- fixing the intermittent errors that popup on the top 2 examples
- making the ISTRUE function to work with a range of cells, eg: A9:C9