Samba PDV + Ubuntu Server 8 = setresuid failed with EAGAIN

Olá pessoal, estou tendo um problema muito chato com o Samba no Ubuntu, determinadas horas o clientes no Windows XP recebem uma mensagem dizendo que o mapeamento está indisponível e o samba loga mensagens como essa abaixo:

[2008/09/05 20:13:49, 0] lib/util_sec.c:set_effective_uid(205)
setresuid failed with EAGAIN. uid(1004) might be over its NPROC limit
[2008/09/05 20:13:49, 0] lib/util_sec.c:assert_uid(101)
Failed to set uid privileges to (-1,1004) now set to (0,0)
[2008/09/05 20:13:49, 0] lib/util.c:smb_panic(1633)
PANIC (pid 5548): failed to set uid

[2008/09/05 20:13:49, 0] lib/util.c:log_stack_trace(1737)
BACKTRACE: 20 stack frames:
#0 /usr/sbin/smbd(log_stack_trace+0x1c) [0x613b1c]
#1 /usr/sbin/smbd(smb_panic+0x43) [0x613c03]
#2 /usr/sbin/smbd [0x618cc1]
#3 /usr/sbin/smbd [0x4ba57e]
#4 /usr/sbin/smbd(pop_sec_ctx+0x96) [0x4ba6f6]
#5 /usr/sbin/smbd(unbecome_root+0x9) [0x4afec9]
#6 /usr/sbin/smbd(gid_to_sid+0x168) [0x5d36b8]
#7 /usr/sbin/smbd(get_nt_acl+0x44a) [0x4c432a]
#8 /usr/sbin/smbd(is_visible_file+0x26e) [0x46e06e]
#9 /usr/sbin/smbd [0x46e5f0]
#10 /usr/sbin/smbd(dptr_ReadDirName+0x54) [0x46e664]
#11 /usr/sbin/smbd [0x4a54b4]
#12 /usr/sbin/smbd [0x4a8ae3]
#13 /usr/sbin/smbd(handle_trans2+0x1be) [0x4a927e]
#14 /usr/sbin/smbd(reply_trans2+0x6ea) [0x4afc3a]
#15 /usr/sbin/smbd [0x4c879e]
#16 /usr/sbin/smbd(smbd_process+0x7e2) [0x4c9b92]
#17 /usr/sbin/smbd(main+0x8cd) [0x6c5f6d]
#18 /lib/libc.so.6(__libc_start_main+0xf4) [0x7fdfd09091c4]
#19 /usr/sbin/smbd [0x45a869]
[2008/09/05 20:13:49, 0] lib/fault.c:dump_core(181)
dumping core in /var/log/samba/cores/smbd


Já pesquisei em vários foruns e nada resolve isso. Minha config é :

[global]
# Nome / grupo
workgroup = grupo
netbios name = servidor
server string = servidor

# Rede
bind interfaces only = yes
domain logons = yes
domain master = yes
dns proxy = No
hosts allow = 10.50.
interfaces = eth0 lo
local master = yes
logon script = netlogon.bat
name resolve order = wins host bcast lmhosts
preferred master = yes
os level = 100
time server = yes
wins support = yes
#logon home =
logon path =

# LOG
log file = /var/log/samba/samba.%m
smb passwd file = /etc/smbpasswd
max log size = 100
log level = 2

# Seguranca
encrypt passwords = true
security = user
enable privileges = yes
passdb backend = tdbsam
passwd program = /usr/bin/smbpasswd %u
null passwords = no
hide unreadable = yes
hide dot files = yes
password level = 6
obey pam restrictions = Yes
pam password change = Yes
passwd chat debug = yes
admin users = root

# Caracteres
unix charset = iso8859-1
display charset = iso8859-1
preserve case = yes
case sensitive = no

# Aumentando o desempenho
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
read raw = yes
write raw = yes
kernel oplocks = No
max xmit = 65535
dead time = 15
getwd cache = yes
max connections = 0

# User management
add user script = /usr/sbin/useradd -m %u
delete user script = /usr/sbin/userdel -r %u
add group script = /usr/sbin/groupadd %g
delete group script = /usr/sbin/groupdel %g
add machine script = /usr/sbin/useradd -s /bin/false -g computador -d /d
ev/null %u
add user to group script = /usr/sbin/usermod -G %g %u
passwd chat = "*Nova senha:*" %n\r "*Nova senha (confirme):*" %n\r \ "*S
enha alterada!*"
force user = %U