failure with "ls" command

Hi all,

I made a usb bootable image.
After booting up, I type in “ls” command and shows…

ls

dev proc tmp usr
Process 4104 (ls) exited status=0

ls # I type in again

No such file or directory

Why does “ls” fail, but it succeds at the first time?

Below is my buildfile

[virtual=x86,bios +compress] .bootstrap = {
startup-bios -s64K
PATH=/proc/boot:/usr/lib LD_LIBRARY_PATH=/proc/boot:/usr/lib procnto -vv
}

[+script] .script = {
seedres

pci-bios &
waitfor /dev/pci

io-usb -dohci -duhci -dehci &
waitfor /dev/io-usb/io-usb

io-hid -dusb
waitfor /dev/io-hid/io-hid

devc-con-hid -n1 &
reopen /dev/con1

pipe &
mqueue &

[+session] esh

}

[type=link] /tmp=/dev/shmem
[type=link] /usr/lib/ldqnx.so.2=/proc/boot/libc.so.3

fs-qnx4.so

libc.so.3
devu-ehci.so
devu-ohci.so
devu-uhci.so
libhiddi.so.1
libusbdi.so.2
devh-usb.so

[code=uip code=copy]
seedres
pci-bios
io-usb
io-hid
devc-con-hid
pipe
mqueue

esh
ls
cd
pwd
df

if I use ksh instead of esh, after executing “ls”, it is locked.

ls

dev proc tmp usr

Process 4105 (ls) exited status=0
locked here!!!

I’ve resolved… miss typing… it should be [data=copy]