Mac OS X: /usr/libexec/cups/filter/rastertospl failed (Samsung ML 1610, 1710, etc.)

This is not a Linux fix, but a Mac OS X "Snow Leopard" one (and it probably also applies to Lion).

After upgrading my parents' Mac Mini to Snow Leopard, their Samsung ML 1610 stopped printing. The print queue showed the error:

/usr/libexec/cups/filter/rastertospl failed

Only after trying to run rastertospl in the Terminal you get to see a helpful error message:

You need the Rosetta software to run rastertospl. The Rosetta installer is in Optional Installs on your Mac OS X installation disc.

After installing this from the install DVD all was working again :-)

I did also re-install the Samsung printer drivers from this Samsung printer drivers for OS X page, but am not sure this was even necessary.