Version:            (using KDE KDE 3.1)
Installed from:    Compiled From Sources
Compiler:          gcc 3.2 
OS:          Linux

It's often necessary to create a raw printer queue on a printer that will be shared using Samba because the driver is on the client side.  However, if we want that this queue prints "raw" documents then we need to uncomment the line "application/octet-stream        application/vnd.cups-raw        0       -" in the /etc/cups/mime.convs file and the line "application/octet-stream" in the /etc/cups/mime.types file.  An other solution is to print using the -oraw option.

When I created a local raw printer with the printing manager, I discovered that it doesn't do this automatically so the newly created raw printed did not work.  I think the printing manager should uncomment these lines when creating a local raw printer or use the -oraw option when printing.

To reproduce, just create a raw printer with these lines commented and try to print a document coming from Samba to the printer.  These lines will appear in the cups log file :
print_job: Unsupported format 'application/octet-stream'!
Hint: Do you have the raw file printing rules enabled?
In my case nothing got printed too.

If this can help you, I'm using a Lexmark Z32 printer (it's not a Postscript printer, but I'll buy one one day...).