Matt,

It is good practice to use "Option Explicit" at the top of each module.
What follows is my slightly modifed version of your code.
I have assumed that "DMDrange" is a named range.
I can't test the code so please let us know how it works for you.

'-----------------------------------------
Sub PrintAllDMDReports_pdf()
Dim CurCell As Range
Dim DMDCell As Range
Dim pdfLocation As String
Dim WeekNo As Integer

Dim SelectedDMD As Variant'*
Dim N_A_DMD As Variant'*

pdfLocation = Sheets("PDF Printing").Range("A11").Value
WeekNo = _
InputBox("Enter the current week no (e.g. 3)", "WeekNumber ")

'Loops through each DMD in the structure and prints
Application.ScreenUpdating = False
Application.Calculation = xlManual

For Each CurCell In Range(DMDrange)
SelectedDMD = CurCell.Value
Sheets("DMD Summary").Activate
Range("C2").Value = SelectedDMD
Range("D2").Activate

' Loops to find #N/A's or other errors and hides them
' Done this way to avoid problems for Excel 97 users as well
For Each DMDCell In Range("B6:B13,B22:B37")
N_A_DMD = DMDCell.Value
If IsError(N_A_DMD) Then
If N_A_DMD = CVErr(xlErrNA) Then
ActiveSheet.DisplayPageBreaks = False'*
DMDCell.Rows.Hidden = True
End If
End If
Next DMDCell

' Prints to the pdf printer & renames to create unique files
Sheets("DMD Summary").PrintOut Copies:=1, Collate:=True
'dir (c:\documents and settings\Name pdfLocation & _
'"Week " & WeekNo & ".pdf" As _
'"h:\DMDs\" & SelectedDMD & ".pdf"
ActiveSheet.DisplayPageBreaks = False'*
Range("B6:B13,B22:B37").Rows.Hidden = False
Next
Application.Calculation = xlAutomatic
Application.ScreenUpdating = True
End Sub
'-----------------------------------------

Regards,
Jim Cone
San Francisco, CA

"Matt Larkin" wrote in message m...
I have some code which loops through a variety of cells determining
whether or not to hide them.
I don't think that the code is particularly inefficient (though by no
means perfect), but what is annoying me is that two machines which are
physically (i.e. processor, HDD, RAM) identical, running the same SP
of Excel 2000 on the same OS run at markedly different speeds. Both
machines are Compaq P4 machines, physically identical inside and out!
(XL 2000, ver 9.0.6926 SP3, Win2K)
The whole process on my "old" PC took about 20 seconds to run. The
whole process on my "new" PC takes closer to 5 minutes.
Is there anything "key" in the Tools, Options (or similar) setups that
might create this difference?
The code is below. I've commented out the references to
screenupdating and calculation modes as changing either / both of
these makes no discernable difference to the speed differential.
Just as a plain old user rightclicking and choosing to hide the
offending rows also exhibits the same turgid speed. Is there any
"dump" of Excel's settings that I can extract to see if there are any
differences?
Cheers!
Matt
-snip -