Comment 40 for bug 561264

OK, that came from my bad guess about what to change. What's happened is that we've killed all the "move down [n] raster rows" commands, and changed them into something else (move up or something probably).

Gavin, can you now do: yum downgrade 'hplip*' 'hpijs*' 'libsane-hp*'
and try changing the "Output Mode" option in the Printer Options for the queue from RGB to Gray? Let us know if that gives correct blank lines.

I think I've found a useful clue in this document:
  "HP PCL/PJL Reference (PCL 5 Color) - Technical Reference Manual (bpl13212)"
  http://h20000.www2.hp.com/bc/docs/support/SupportManual/bpl13212/bpl13212.pdf

Take a look at page 139, specifically this bit:

This command zero-fills the offset area. For color printers, zero-fills
are filled with the color of index 0, which is not necessarily white.

So I wonder if this is some problem with the indexed colour palette getting its colours in a twist.