When I print from a program such as Evince, after I press print, but before the job is sent to the printer, I'm prompted for a username/password. When I print from Libreoffice, the print job just sits in the queue forever. The following goes to CUPS' error_log:
E [07/Apr/2012:13:44:21 +0100] [Job 108] Tree connect failed (NT_STATUS_ACCESS_DENIED)
I guess CUPS is sending the job on to the Windows system that the printer is attached to without attempting to authenticate.
Here's the contents of CUPS' printers.conf:
MakeModel Samsung CLP-300 Foomatic/foo2qpdl (recommended)
JobSheets none none
This might have a duplicate in bug #53029.
*** This bug has been marked as a duplicate of bug 53029 ***