Samba does not work after upgrade

Question

I am migrating a SuSE server to a new virtual environment. This also includes upgrading to a new version of samba. The old version of smbd is 2.2.8, the new has 3.6.3. The "new" SuSE is SLES 11.4.

The smb.conf, smbusers and smbpasswd were copied verbatim. The samba service starts normally, for example with service smb restart. From a client, I can perform NET USE * \\new_server\share which executes normally, assigning a Z: drive which does become visible in Windows Explorer. When I try to access it from the Explorer, or from the command line with DIR Z: , I am rewarded with "An unexpected network error occurred".

Here is the global section of smb.conf:

[global]
 workgroup = XXXXXX
 security = share
 guest ok = yes
 guest account = xxxx
 os level = 0
 encrypt passwords = yes
 socket options = SO_KEEPALIVE IPTOS_LOWDELAY TCP_NODELAY
 wins support = no
 ; plus a few that seem irrelevant, such as code pages

And here is a typical share declaration:

[PDF]
 path = /home/xxx/PDF
 public = yes
 writable = yes
 printable = no
 create mask = 0765

Things already tried, none making any difference:

• forcing SMB2 with min protocol = SMB2 in the global secition

• adding guest ok = yes and browseable = yes to the share declaration