ubuntu install ejabberd 2.1.3 success ,but start error

{error_logger,{{2010,5,29},{18,7,12}},"Protocol: ~p: register error: ~p~n",["inet_tcp",{{badmatch,{error,duplicate_name}},[{inet_tcp_dist,listen,1},{net_kernel,start_protos,4},{net_kernel,start_protos,3},{net_kernel,init_node,2},{net_kernel,init,1},{gen_server,init_it,6},{proc_lib,init_p_do_apply,3}]}]}
{error_logger,{{2010,5,29},{18,7,12}},crash_report,[[{initial_call,{net_kernel,init,['Argument__1']}},{pid,<0.21.0>},{registered_name,[]},{error_info,{exit,{error,badarg},[{gen_server,init_it,6},{proc_lib,init_p_do_apply,3}]}},{ancestors,[net_sup,kernel_sup,<0.9.0>]},{messages,[]},{links,[#Port<0.115>,<0.18.0>]},{dictionary,[{longnames,false}]},{trap_exit,true},{status,running},{heap_size,610},{stack_size,24},{reductions,481}],[]]}
{error_logger,{{2010,5,29},{18,7,12}},supervisor_report,[{supervisor,{local,net_sup}},{errorContext,start_error},{reason,{'EXIT',nodistribution}},{offender,[{pid,undefined},{name,net_kernel},{mfa,{net_kernel,start_link,[['ejabberd@localhost',shortnames]]}},{restart_type,permanent},{shutdown,2000},{child_type,worker}]}]}
{error_logger,{{2010,5,29},{18,7,12}},supervisor_report,[{supervisor,{local,kernel_sup}},{errorContext,start_error},{reason,shutdown},{offender,[{pid,undefined},{name,net_sup},{mfa,{erl_distribution,start_link,[]}},{restart_type,permanent},{shutdown,infinity},{child_type,supervisor}]}]}
{error_logger,{{2010,5,29},{18,7,12}},std_info,[{application,kernel},{exited,{shutdown,{kernel,start,[normal,[]]}}},{type,permanent}]}
{"Kernel pid terminated",application_controller,"{application_start_failure,kernel,{shutdown,{kernel,start,[normal,[]]}}}"}

Crash dump was written to: /usr/local/ejabberd/var/log/ejabberd/erl_crash_20100529-180711.dump
Kernel pid terminated (application_controller) ({application_start_failure,kernel,{shutdown,{kernel,start,[normal,[]]}}})