Getting PAM up inside chroot issues

[Unga]

Hi all

I'm trying to getting PAM up inside a chroot. I'm using FreeBSD 7.0 on i386.

su -l shows following error:
su: pam_start: system error

strace su -l shows following failures:
access("/etc/localtime", R_OK)          = 0
open("/etc/localtime", O_RDONLY)        = 4
fstat(4, {st_mode=S_IFLNK|S_ISGID|052, st_size=18445798717047743530, ...}) = 0
read(4, "3\244\374\377*\244\374\3773\244\374\3773\244\374\3773\244"..., 7944) = 171
close(4)                                = 0
socket(PF_UNIX, SOCK_DGRAM, 0)          = 4
fcntl(4, F_SETFD, FD_CLOEXEC)           = 0
connect(4, {sa_family=0xa4 /* AF_??? */, sa_data="\374\377\\[x\0%02x\0%1x"}, 106) = -1 ENOENT (No such file or directory)
connect(4, {sa_family=0x2f /* AF_??? */, sa_data="ystem call\0Inp"}, 106) = -1 ENOENT (No such file or directory)
connect(4, {sa_family=0x74 /* AF_??? */, sa_data="d processes\0Re"}, 106) = -1 ENOENT (No such file or directory)
close(4)                                = 0
sendto(-1, "source deadlock avoided\0Cannot a"..., 72, 0, NULL, 0) = -1 EBADF (Bad file descriptor)
socket(PF_UNIX, SOCK_DGRAM, 0)          = 4
fcntl(4, F_SETFD, FD_CLOEXEC)           = 0
connect(4, {sa_family=0x6c /* AF_??? */, sa_data="nk\0\0\0\0Operatio"}, 106) = -1 ENOENT (No such file or directory)

There is no failure up to reading the  /etc/localtime.

This shows the socket (fd=4) disappeared before the connect. 

What am I still missing in my chroot? Where does this socket get created? is it the current directory where su initiated or somewhere else? 

Appreciate your help to identify the cause.

Kind regards
Unga