I've never seen that happen before. So you're saying if you do a print preview, the tax shows up as zero, but if you actually printed the paper, it prints out correctly? That's weird. Let me ask, did you run down the troubleshooter? Have you rebooted lately? Compacted and repaired the database? That kind of stuff that just seems like one of those weird quirky errors. Could be caused by anything from a memory leak to just a bug somewhere. Maybe try an office update too. Whenever people encounter something weird, I always tell them to just run down the troubleshooter, and 9 times out of 10, the problem goes away. Also, can you replicate this with other purchase orders? Is it just that one or other ones doing the same thing?

Mick,
Just to make sure, the print preview and the paper-printed report are coming from the same Access report, correct?

I've seen differences in value sometimes if you open it up in normal report view because Access doesn't always run all the calculations in report view. But in print preview mode, it should look exactly as it's going to print out. So, it's got to be a bug or a glitch.

Its wierd but as long as the report prints out ok I can live with it. I wonder if its the command button. The reason I say this is because once the report is opened in print preview...if I right mouse and change to report or layout view the sales Tax amount is as it should be and the PO Order Total is correct. The VBA I have on the button is

Private Sub InvoiceBtn_Click()

    Me.Refresh
    DoCmd.OpenReport "PurchaseOrderInvoice2R", acViewPreview
    
End Sub

Or may be because I have the Sales Tax on the report to this

=[Forms]![PurchaseOrderF]![PurchaseOrderDetailF].[Form]![SalesTax]

Just responding to a question in your first comment...It does the same thing in all the purchase orders

As long as that form is open when you preview the report it should get the value correctly

Think I have solved it. I removed the me.refresh from the command Burron VBA code and it seems to work OK now