ok, one next step done...
Network path is found, but the last problem (I think), when I trying to log as 'root' it returns that can't find username and in /var/log/samba/log.client-winxp the following entry is logged
[2008/03/18 18:57:46, 0] passdb/pdb_interface.cdb_default_create_user(329)
_samr_create_user: Running the command `/usr/sbin/smbldap-useradd -w "client-winxp$"' gave 9
when I invoke the command manually I get this:
host# /usr/sbin/smbldap-useradd -w "client-winxp$"
/usr/sbin/smbldap-useradd: user client-winxp$ exists
What's interesting that when I'm logging as anyone else or give 'root' incorect password it returns 'incorrect users/password', so it seems that 'root' is authorized correctly, but somehow is dropped at some kind of next stage ...