[Samba] trusted domain 'disconnected' using winbind

[Grund, Andreas]

I have a problem with winbind resolving global groups on a trusted NT
Domain. I want to use SQUID and NTLM Authentification and therefore the
external authentification helper needs to check if a user belongs to a given
group. When I do 'windbind -r DOMAIN+USER GROUP', only groups of the local
domain are listed. It seems as if winbind couldn't find a domain controller
for the trusted domain: 'wbinfo --sequence' shows the trusted domain
disconnected. Debugging winbindd does show following errors:

wbinfo --sequence	=>
[..]
bind_rpc_pipe: transfer syntax differs
rpc_pipe_bind: check_bind_response failed.
[..]
Could not open a connection to DOMAIN_B for \PIPE\samr
(NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND)

wbinfo -g		=>
get_sam_group_entries: could not enumerate domain groups! Error:
NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND

Though winbind couldn't find a Domain Controller, checking Password secrets
using 'winbind -a' works without any problems for members of both domains.

Has anyone an idea how to solve this problem?

Samba Version: 3.0.9-2.6-SUSE
2 NT4 SP6 Servers acting as PDC for 2 trusted Domains

Thx
Andi