Custom Printing

Hi!
I have a problem with custom printing in windows forms application. I want
to print a large image to big printer (plotter) with custom paper size
settings.
This my code:
....
PrintDlg as System.Windows.Forms.PrintDialog PrintDoc As
System.Drawing.Printing.PrintDocument
PrintDlg.Document = PrintDoc
....
'show a print dialog
PrintDlg.ShowDialog()

'this property has a selected paper name
PrintDoc.DefaultPageSettings.PaperSize.PaperName

'these properties have a paper size
PrintDoc.DefaultPageSettings.Bounds.Width
PrintDoc.DefaultPageSettings.Bounds.Height

And now. If at print dialog box I select one of the standart paper size,
these properties return valid values. But if I select CUSTOM and enter own
custom size values it returns PaperName=custom and Width and Height not
values which I entered at Print Dialog Box.

What's wrong?

I use Microsoft Visual Studio 2005. .Net Framework 2.0.50727 SP1

Sorry for my Bad English.