Local machine is CentOS 5.4, with samba 3.5.2 rpms from sernet.

Remote machine is samba 3.0.30 set up with share level security with this smb.conf
	[global]
	workgroup = WORKGROUP
	security = share     (changing this to "user" eliminates the problem)
	[tmp]
	path = /tmp
	guest ok = yes


On local machine:
$ smbclient '\\srv\tmp' -U%
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.0.30-1abc]
Server not using user level security and no password supplied.
Segmentation fault
$


gettimeofday({1271602314, 355110}, NULL) = 0
gettimeofday({1271602314, 355320}, NULL) = 0
select(11, [8 10], [], NULL, {19, 998200}) = 1 (in [10], left {19, 998000})
gettimeofday({1271602314, 357511}, NULL) = 0
recv(10, "\0\0\0l", 4, 0)               = 4
gettimeofday({1271602314, 357950}, NULL) = 0
gettimeofday({1271602314, 358148}, NULL) = 0
select(11, [8 10], [], NULL, {19, 995372}) = 1 (in [10], left {19, 995372})
gettimeofday({1271602314, 358732}, NULL) = 0
recv(10,"\377SMBs\0\0\0\0\210\1\300\0\0\0\0\0\0\0\0\0\0\0\0\377\377\304r\0\0\3\
0"..., 108, 0) = 108
write(3, "Domain=[WORKGROUP] OS=[Unix] Ser"..., 56Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.0.30-1abc]
) = 56
write(3, "Server not using user level secu"..., 63Server not using user level security and no password supplied.) = 63
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++


...
Connecting to 192.168.1.119 at port 445
Socket options:
        SO_KEEPALIVE = 0
        SO_REUSEADDR = 0
        SO_BROADCAST = 0
        TCP_NODELAY = 1
        TCP_KEEPCNT = 9
        TCP_KEEPIDLE = 7200
        TCP_KEEPINTVL = 75
        IPTOS_LOWDELAY = 0
        IPTOS_THROUGHPUT = 0
        SO_SNDBUF = 16384
        SO_RCVBUF = 87380
        SO_SNDLOWAT = 1
        SO_RCVLOWAT = 1
        SO_SNDTIMEO = 0
        SO_RCVTIMEO = 0
        TCP_QUICKACK = 1
 session request ok
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.0.30-1abc]
 session setup ok
Server not using user level security and no password supplied.
Segmentation fault