Comment 2 for bug 539162

I have the exact same problem, but I am using Jaunty with the latest updates at the time of this comment. My PDFs look just like the attached example.

I only get the mangled PDF when I choose "Gray" as the color mode. (Possible choices are Binary, Gray, Color.) Surprisingly, Color mode scans to a PDF just fine.

When choosing the action (view, save, copy, etc), the Viewer mode works just fine for the PDF, but upon save, it gets mangled (when using Grey).

Neither 100 dpi nor 300 dpi make a difference.

I've also changed Preferences > Setup > Filetype > "Save PDF zlib compressed" to false (unchecked). This had no effect.

For the mangled PDFs (and the successful color ones), Evince shows the "Format" as "PDF-1.4"

When loading *any* PDF that was created with xsane (gray or color) in Evince from the command line, I get a lot of errors like these:

  Error (1734109): Illegal character <b1> in hex string
  Error (1734110): Illegal character <87> in hex string
  Error (1734111): Illegal character <af> in hex string
  Error (1734112): Illegal character <86> in hex string

Even PDFs made with xsane 0.995 would print these errors to the console in Evince. (Yet 0.995 scanned grayscale just fine.)

However, the non-mangled PDFs saved by xsane will load without error in GhostScript.

In GhostScript, the mangled PDFs error upon view and do not display. ("Error: /syntaxerror in ID" .... plus stack values)

This seems to only affect Grayscale PDF files generated with xsane; saving to PostScript, PNG, JPG work fine. Xsane PDFs have always been bloated. A single-page grayscale document weighs in around 1.5MB. Yet if I send that (unmangled) PDF through GhostScript, it reduces it to 100KB.

This is how I do the PDF conversion with GhostScript:
  gs -dBATCH -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=gs.pdf xsane.pdf

xsane version: 0.996-1ubuntu2
Scanner: Epson RX500