Hmmm... "Ascii filter options" is something in OpenOffice, are you trying to import this PDF into OpenOffice? The PDF support in OpenOffice is still in a BETA stage so it's not really ready for general use... See more about it here:
http://wiki.services.openoffice.org/...t_PDF_files%3F
You should use a program like 'evince' or 'kpdf' to open your PDF file. You won't be able to edit the file but these programs are excellent PDF readers.