rest call /controller/addNode aborted

automation is loading data, and attempts a rebalance in. (log.1) log excerpt:

[menelaus:warn] [2012-04-20 12:21:23] [n_0@10.2.2.166:<0.19238.1>:menelaus_web:loop:358] Server error during processing: ["web request failed",

{path,"/controller/addNode"}

,

{type,exit}

,
{what,
{{{{badmatch,
{aborted,

{bad_type,cluster,disc_copies, 'n_0@10.2.2.166'}

}},
[{mb_mnesia,ensure_config_tables,0,
[

{file,"src/mb_mnesia.erl"},
{line,405}]},
{mb_mnesia,init,1,
[{file,"src/mb_mnesia.erl"}

,

{line,261}

]},
{mb_mnesia,handle_call,3,
[

{file,"src/mb_mnesia.erl"}

,

{line,138}

]},
{gen_server,handle_msg,5,
[

{file,"gen_server.erl"},{line,578}]},
{proc_lib,init_p_do_apply,3,
[{file,"proc_lib.erl"},{line,227}]}]},
{gen_server,call,
[mb_mnesia,
{maybe_rename,"10.2.2.166"},
30000]}},
{gen_server,call,
[ns_cluster,
{add_node,"127.0.0.1",9001,
{"Administrator","password"}},
65000]}}},
{trace,
[{gen_server,call,3,
[{file,"gen_server.erl"}

,

{line,188}

]},
{ns_cluster,add_node,3,
[

{file,"src/ns_cluster.erl"}

,

{line,70}

]},
{menelaus_web,handle_add_node,1,
[

{file,"src/menelaus_web.erl"},
{line,1673}]},
{menelaus_web,loop,3,
[{file,"src/menelaus_web.erl"}

,

{line,333}

]},
{mochiweb_http,headers,5,
[

{file,"mochiweb_http.erl"}

,

{line,136}

]},
{proc_lib,init_p_do_apply,3,
[

{file,"proc_lib.erl"}

,

{line,227}

]}]}]