[erlang-questions] Progra mming Erlang problem:sasl doesn't work on my laptop with Ubuntu8.04

[wenew zhang]

> erl -boot start_sasl -config  elog3
elog3.config:
%% rotating log and minimal tty
[{sasl, [
	 {sasl_error_logger, false},	
	 %% define the parameters of the rotating log
	 %% the log file directory
	 {error_logger_mf_dir,"/home/joe/error_logs"},	
         %% # bytes per logfile
	 {error_logger_mf_maxbytes,10485760}, % 10 MB
         %% maximum number of logfiles
	 {error_logger_mf_maxfiles, 10}
	]}].


Eshell V5.5.5  (abort with ^G)
1> sellaprime_supervisor:start_in_shell_for_testing().
*** my_alarm_handler init:{xyz,{alarm_handler,[]}}
area_server starting
prime_server starting
true
2> area_server:area({square,10}).
100
3> area_server:area({rectangle,10,20}).
area_server stopping

6> error_logger:error_msg("This is an error~n").
ok
=ERROR REPORT==== 27-Mar-2008::11:47:57 ===
This is an error

7> rb:start().
{error,{"cannot read the index file",
        {child,undefined,
               rb_server,
               {rb,start_link,[[]]},
               temporary,
               brutal_kill,
               worker,
               [rb]}}}
8>

why can't start rb? and can't create  error_logs under /home/joe/