Erlang application exit,, but vm is still running - erlang

Question

My Erlang applicaation processed crashed and then exited, but found that the erlang VM is still running.
I could recieve pong when ping this "suspended node"
Types regs() and the results show below, there is not my app process.
(hub#192.168.1.140)4> regs().
** Registered procs on node 'hub#192.168.1.140' **
Name Pid Initial Call Reds Msgs
application_controlle <0.7.0> erlang:apply/2 30258442 1390
auth <0.20.0> auth:init/1 189 0
code_server <0.26.0> erlang:apply/2 1194028 0
erl_epmd <0.19.0> erl_epmd:init/1 138 0
erl_prim_loader <0.3.0> erlang:apply/2 2914236 0
error_logger <0.6.0> gen_event:init_it/6 49983527 0
file_server_2 <0.25.0> file_server:init/1 16185407 0
global_group <0.24.0> global_group:init/1 107 0
global_name_server <0.13.0> global:init/1 1385 0
gr_counter_sup <0.43.0> supervisor:gr_counter_sup 253 0
gr_lager_default_trac <0.70.0> gr_counter:init/1 121 0
gr_lager_default_trac <0.72.0> gr_manager:init/1 46 0
gr_lager_default_trac <0.69.0> gr_param:init/1 117 0
gr_lager_default_trac <0.71.0> gr_manager:init/1 46 0
gr_manager_sup <0.45.0> supervisor:gr_manager_sup 484 0
gr_param_sup <0.44.0> supervisor:gr_param_sup/1 253 0
gr_sup <0.42.0> supervisor:gr_sup/1 237 0
inet_db <0.16.0> inet_db:init/1 749 0
inet_gethost_native <0.176.0> inet_gethost_native:serve 4698517 0
inet_gethost_native_s <0.175.0> supervisor_bridge:inet_ge 41 0
init <0.0.0> otp_ring0:start/2 30799457 0
kernel_safe_sup <0.35.0> supervisor:kernel/1 278 0
kernel_sup <0.11.0> supervisor:kernel/1 47618 0
lager_crash_log <0.52.0> lager_crash_log:init/1 97712230 0
lager_event <0.50.0> gen_event:init_it/6 1813660437 0
lager_handler_watcher <0.51.0> supervisor:lager_handler_ 358 0
lager_sup <0.49.0> supervisor:lager_sup/1 327 0
net_kernel <0.21.0> net_kernel:init/1 110769667 0
net_sup <0.18.0> supervisor:erl_distributi 313 0
os_cmd_port_creator <0.582.0> erlang:apply/2 81 0
rex <0.12.0> rpc:init/1 15653480 0
standard_error <0.28.0> erlang:apply/2 9 0
standard_error_sup <0.27.0> supervisor_bridge:standar 41 0
timer_server <0.100.0> timer:init/1 59356077 0
user <0.31.0> group:server/3 23837008 0
user_drv <0.30.0> user_drv:server/2 12239455 0
** Registered ports on node 'hub#192.168.1.140' **
Name Id Command
ok
It rarely occurs, but anyone explains it?
System: CentOS 5.8
Erlang: R15B03