I get a NullReferenceException from the UltraWinGrid, when clicking the Print button in the PrintPreview dialog. The preview output looks fine. My Code is:

UltraGridLayout ugLayout = new UltraGridLayout();
ugLayout.Reset();

UltraGridPrintDocument ugPrintDoc = new UltraGridPrintDocument();
ugPrintDoc.DocumentName = filterName;
ugPrintDoc.Grid = dgBrowseResult;

// Header with:
// <browsing ts>  <filterName>  <printing ts>

HeaderFooterPageSection ugpdHeader = ugPrintDoc.Header;

ugpdHeader.TextLeft = "TimestampBrowsing " + filterAppliedAt.ToString();

ugpdHeader.TextRight = "TimestampPrinting " + DateTime.Now.ToString();

ugpdHeader.TextCenter = filterName + "\n" + criteria + "\n" + printingAllRows;

dgBrowseResult.PrintPreview(ugLayout, ugPrintDoc);

The error log is:

2008-01-08 10:46:34,734 [2700] ERROR DEV-LOG PrintResultList - System.NullReferenceException: Object reference not set to an instance of an object.
   at Infragistics.Win.UltraWinGrid.PrintManager.CalculateFirstRows()
   at Infragistics.Win.UltraWinGrid.PrintManager.CalculatePageDimensions()
   at Infragistics.Win.UltraWinGrid.PrintManager.BeginPrint(Object sender, PrintEventArgs e)
   at System.Drawing.Printing.PrintDocument.OnBeginPrint(PrintEventArgs e)
   at Infragistics.Win.Printing.UltraPrintDocument.OnBeginPrint(PrintEventArgs e)
   at Infragistics.Win.UltraWinGrid.UltraGridPrintDocument.OnBeginPrint(PrintEventArgs e)

The error does not occur if I omit the PrintDocument parameter: dgBrowseResult.PrintPreview(ugLayout)

But I need to print the header as well!

Thanks in advance for any hint.

Holger 

using: VS 2003, C#, .Net 1.1, Infragistics NetAdvantage 2006 Volume 3 CLR 1.x