[Samba] Problems with accessing samba printer from Windows

[bill purvis]

Hi,
I recently migrated from Madrake/Mandriva to Ubuntu (8.04) on the
machine with the printer attached. When I set up samba originally
my understanding of it was very limited. It's probably even more
limited now (brain cells dying off! :-) ). However, at least it
did what I wanted - gave access to the printer and a scratch disk
area for the Windows machines. When I migrated to Ubuntu, I copied
the bits I thought relevant into the distributed smb.conf and started 
it up. I didn't get around to testing the Windows access until today.
When I tried to print or open the scratch area on Windows it fails to
make the connection. I tried deleting the printer entry and re-creating
it with 'add printer' but that failed also. I've check the various
log files on the server and found lines like:

  idmap uid range missing or invalid
  idmap will be unable to map foreign SIDs
[2008/11/14 16:52:34, 0] nsswitch/idmap.c:idmap_alloc_init(750)
  ERROR: Initialization failed for alloc backend, deferred!

that was in the log.winbindd-idmap file. Nothing else notable.
I'm attaching a copy of the essential bits of the smb.conf file
as listed by testparm. I'd be grateful if someone who knows more
about samba can advise me what to try next.

Many thanks,
Bill

----------------------smb.conf------------------------------------------
[global]
	server string = Samba Server %v
	map to guest = Bad User
	log file = /var/log/samba/log.%m
	max log size = 50
	socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
	dns proxy = No
	hosts allow = 192.168.1., 192.168.2., 127.

[homes]
	comment = Home Directories
	read only = No
	browseable = No

[printers]
	comment = All Printers
	path = /var/spool/samba
	create mask = 0700
	guest ok = Yes
	printable = Yes
	browseable = No

[print$]
	path = /var/lib/samba/printers
	write list = @adm, root
	inherit permissions = Yes
	guest ok = Yes

[pdf-gen]
	comment = PDF Generator (only valid users)
	path = /var/tmp
	printable = Yes
	printing = bsd
	print command 
= /usr/share/samba/scripts/print-pdf "%s" "%H" "//%L/%u" "%m" "%I" "%J" &
	lpq command = /bin/true
	lprm command = lprm -P'%p' %j

[backups]
	comment = Backup Disk 1
	path = /back1
	read only = No
	guest ok = Yes
----------------------------------------------------------
-- 
+---------------------------------------+
| Bill Purvis, Model Engineer           |
|  email: bill at billp.org                |
+---------------------------------------+