[Samba] Permission error again

[Peter Blajev]

Samba-3.0.7 on RedHat Enterprise Linux ES release 3.

I'm trying to change printer driver:
===
[93,burfile:/etc/samba] => rpcclient -U root burprint
Password:
rpcclient $> setdriver ccplp0 "HP LaserJet 5"
result was WERR_ACCESS_DENIED
rpcclient $> 
===

Why am I getting this error?
Nothing in the log files. "use client driver" is set to No.
Even I'm connecting as root I checked all folders system permissions
and everything looks good.

Here is the relevant (I think) part of smb.conf file:
===
[print$]
     comment            = Printer Driver Download Area
     path               = /etc/samba/drivers
     browseable         = no
     guest ok           = yes
     read only          = yes
     write list         = root, @printadm
     create mode        = 0664
     directory mode     = 0775
     force group        = printadm
===

I'm out of ideas.
Please any suggestion, hint, tip... :-)

Thank you
Peter Blajev