Here's an strace of tcpdump with nscd running:

[root@mycroft /root]# strace /usr/sbin/tcpdump -i eth0 \
host cais
execve("/usr/sbin/tcpdump", ["/usr/sbin/tcpdump", "-i",
"eth0", "host", "cais"], [/* 21 vars */]) = 0
brk(0)                                  = 0xda87c
open("/etc/ld.so.preload", O_RDONLY)    = -1 ENOENT (No such
file or directory
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=19057, ...}) = 0
mmap(0, 19057, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7001a000
close(3)                                = 0
open("/lib/libc.so.6", O_RDONLY)        = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=4237650, ...}) = 0
read(3, "\177ELF\1\2\1\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192
mmap(0, 1065572, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) =
0x7002a000
mprotect(0x70112000, 115300, PROT_NONE) = 0
mmap(0x7011a000, 65536, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_FIXED, 3, 0xe0000) = 0x7011a000
mmap(0x7012a000, 16996, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7012a000
close(3)                                = 0
munmap(0x7001a000, 19057)               = 0
personality(PER_LINUX)                  = 0
getpid()                                = 5144
time(NULL)                              = 928124111
getpagesize()                           = 0x2000
brk(0)                                  = 0xda87c
brk(0xda8a4)                            = 0xda8a4
brk(0xdc000)                            = 0xdc000
open("/etc/localtime", O_RDONLY)        = 3
read(3, "TZif\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 44) = 44
read(3, "\234\275\1\360\234\344d\300\236\270"..., 920) = 920
read(3, "\0\1\0\1\0\1\0\1\0\1\0\1\0\1\0\1"..., 230) = 230
fstat(3, {st_mode=S_IFREG|0644, st_size=1218, ...}) = 0
mmap(0, 8192, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7001a000
read(3, "\377\377\307\300\1\0\377\377\271"..., 8192) = 24
close(3)                                = 0
munmap(0x7001a000, 8192)                = 0
socket(PF_INET, SOCK_PACKET, 0x3 /* IPPROTO_??? */) = 3
bind(3, {sin_family=AF_INET, sin_port=htons(25972),
sin_addr=inet_addr("104.48.0.0")}, 16) = 0
ioctl(3, SIOCGIFHWADDR, 0xeffffad8)     = 0
ioctl(3, SIOCGIFMTU, 0xeffffad8)        = 0
ioctl(3, SIOCGIFFLAGS, 0xeffffad8)      = 0
ioctl(3, SIOCSIFFLAGS, 0xeffffad8)      = 0
socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 4
ioctl(4, SIOCGIFADDR, 0xeffffad8)       = 0
ioctl(4, SIOCGIFNETMASK, 0xeffffad8)    = 0
close(4)                                = 0
getuid()                                = 0
setuid(0)                               = 0
brk(0xe2000)                            = 0xe2000
ioctl(0, TCGETS, {B38400 opost isig icanon echo ...}) = 0
gettimeofday({928124111, 57304}, NULL)  = 0
getpid()                                = 5144
open("/etc/resolv.conf", O_RDONLY)      = 4
fstat(4, {st_mode=S_IFREG|0644, st_size=71, ...}) = 0
mmap(0, 8192, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7001a000
read(4, "search dsm.space.gc.ca\nnameserv"..., 8192) = 71
read(4, "", 8192)                       = 0
close(4)                                = 0
munmap(0x7001a000, 8192)                = 0
socket(PF_UNIX, SOCK_STREAM, 0)         = 4
connect(4, {sun_family=AF_UNIX,
sun_path="/var/run/.nscd_socket"}, 110) = 0
write(4, "\0\0\0\2\0\0\0\4\0\0\0\5", 12) = 12
write(4, "cais\0", 5)                   = 5
read(4, "\0\0\0\0\0\0\0\1\0\0\0\25\0\0\0\0"..., 32) = 32
readv(4, [{"cais.dsm.space.gc.ca\0", 21}, {"", 0},
{"\n\24J\327", 4}, {"\0\0\0\0\0\0\0\0\0\0\377\377\n\24"...,
16}], 4) = 41
read(4, NULL, 0)                        = 0
close(4)                                = 0
--- SIGBUS (Bus error) ---
+++ killed by SIGBUS +++
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Without nscd it works fine:

[root@mycroft /root]# /etc/rc.d/init.d/nscd stop
Stopping Name Switch Cache Daemon: nscd
[root@mycroft /root]#  /usr/sbin/tcpdump -i eth0 host cais
tcpdump: listening on eth0
00:17:48.456653 mycroft.dsm.space.gc.ca.1048 >
cais.dsm.space.gc.ca.domain: 62112+ (38)
00:17:48.457028 cais.dsm.space.gc.ca.domain >
mycroft.dsm.space.gc.ca.1048: 62112* 1/1/1 (99) (DF)
[SNIP]

6 packets received by filter
0 packets dropped by kernel
[root@mycroft /root]#