run on more nodes error

[cabin_jc@gmail_com]

Hello, everyone
when i ran a case on one node, it worked well. i used the generic_linux_pgi.run's script. When i run the baby on more nodes, it couldn't stop. what's the problem?

Command from $CASENAME.$MACH.run:
/usr/local/openmpi-1.4.2-pgi/bin/mpirun -hostfile /mnt/test/myhost -np 16 ./ccsm.exe >&! ccsm.log.$LID

myhost |
----------------------------------------
node01 slots=16 | OK
----------------------------------------
node02 slots=16 | OK
----------------------------------------
node01 slots=8 |
node02 slots=8 | Could not stop

Why?
Good luck and best wishes to everyone!