I have printing disabled (load printers = no, commented the printer share) in Samba but still puts lots of lines like this in the syslog:
May 29 16:31:02 home smbd[9505]: [2011/05/29 16:31:02, 0] printing/print_cups.c:cups_connect(69)
May 29 16:31:02 home smbd[9505]: Unable to connect to CUPS server localhost:631 - Connection refused
After trying many things, this worked for me:
load printers = no #(this alone isn't enough)
show add printer wizard = no
printing = none
printcap name = /dev/null
disable spoolss = yes