When you print a document, and check the "print to file" checkbox, you get to
choose between Postscript and PDF.  When you select PDF and save the file, you
don't actually get a PDF document.  The Adobe Acrobat reader gives the following
error:

File does not begin with '%PDF-'.

This error is because it is actually creating a Postscript file, and all it is
really doing is putting a pdf extension on it.  The Ghostview viewer will read
and display the resulting document just fine, further proving that it is not a
PDF, but a Postscript file.  PDF generation from OpenOffice is a much needed
feature, as Adobe is unlikely to bring Acrobat over to other platforms besides
Windows.