title: Code running more slowly than on other files / dates
body: <p>I ran the below code looped for 6.5 thousand cells of criteria which are looked up against the range contained on the "LISTS" tab refered to.  This range is some 20 thousand rows.</p>
  
  <p>I ran the code numerous times yesterday in a test file and it ran very quickly.  Maybe 2 minutes: if that.</p>
  
  <p>Today, after deciding I was happy with the code, I've PASTED it (caps there because I'm wondering if that has something to do with it) into my main project.
  Now when I run the code, it takes 2 hours plus!</p>
  
  <p>I didn't change any of the code except for sheet names.</p>
  
  <p>Does anyone know of any reason for this that I'm missing?</p>
  
  <p>I'm new to VBA so I'm suspecting it's some rookie error somewhere!</p>
  
  <pre><code>Dim x As Long
  x = WorksheetFunction.CountA(Columns(1))
  
  'define string length for CELL loop
  Dim char As Integer
  char = Len(ActiveCell)
  
  'define cell loop name
  Dim counter As Integer
  
  'Begin RANGE loop
  For Each cell In Range("b1:b" &amp; x)
      cell.Activate
  
      'Incorporate CELL loop
      For counter = 1 To char
          'Determine if numeric value present in cell = TRUE or FALSE
          If IsNumeric(Right(Mid(ActiveCell, 1, counter), 1)) = True Then
              ActiveCell.Offset(0, 1).Value = Right(ActiveCell.Offset(0, 0), Len(ActiveCell.Offset(0, 0)) - counter + 1)
              Exit For
          Else
              ActiveCell.Offset(0, 1).Value = ActiveCell.Offset(0, 0)
          End If
      Next
  Next
  </code></pre>