samba - Aug 2011 - file share yes, printer no, after upgrade

Hi All,

I used to have Ubuntu 10.04, the samba was configured to provide file
share and printer to both Linux and Windows clients.

After upgrading to Ubuntu 10.10 (marverick), I have the built in Samba
3.5.4 and CUPS 1.4.4 installed.
Configuration file is untouched, however, windows clients are not able
to connect to the printer(file share OK).
Linux clients are working perfectly.

The following is my smb.conf:
[global]
        load printers = Yes
        printcap = cups
        printing = cups
        workgroup = COMPNET
        server string = %h server (Samba, Ubuntu)
        passdb backend = smbpasswd:/etc/samba/smbpasswd
        log file = /var/log/samba/log.%m
        max log size = 500
        dns proxy = No
        panic action = /usr/share/samba/panic-action %d
        cups options = raw
        socket options = TCP_NODELAY

[homes]
        comment = Home Directories
        read only = No
        browseable = No
        valid users = %S

[data]
        comment = Shared drive for the lab
        path = /compnetlab/publicshare
        force user = nobody
        force group = users
        read only = No
        create mask = 0770

[printers]
        valid users = +users
        comment = HP LaserJet 4250
        path = /var/spool/samba
        create mask = 0777
        printable = Yes
        browseable = Yes



I'm wondering what cause the problem.
Any input appreciated.
Thanks in advance!

Best,
ericyosho