printtool fails to provide postscript for some setups (24bit) printtool fails to build postscript.cfg correctly such that COLOR=-d\nBitsPerPixel=24 appear on one line - I will/have posted a suggested fix
A printtool update that shipped with some versions of 5.1 was broken. Please update to the latest printtool available for RH5.1 at ftp://updates.redhat.com/5.1/noarch, or alternatively use the version for RH 5.2.