No GUI error on attempt to create membase bucket on already used port

Build 3.1-19
No GUI error on attempt to create membase bucket on already used port, though buvket is not created and log error is generated:

Server error during processing: ["web request failed",

{path,"/pools/default/buckets"}

,

{type,exit}

, {what, {timeout, {gen_fsm,sync_send_event, [

{global,ns_orchestrator}

, {create_bucket,membase,"test2membase2", [

{num_replicas,1}

,

{ram_quota,314572800}

,

{hdd_quota,2147483648}

,

{auth_type,none}

,

{moxi_port,11209}

]}, 20000]}}}, {trace, [

{gen_fsm,sync_send_event,3}

,

{menelaus_web_buckets, handle_bucket_create,2}

,

{menelaus_web,loop,3}

,

{mochiweb_http,headers,5}

,

{proc_lib,init_p_do_apply,3}

]}] menelaus_web019 13:25:02 - Wed Sep 15, 2010
Client-side error-report for user "Administrator" on node 'ns_1@192.168.1.96': User-Agent:Mozilla/5.0 (Windows; U; Windows NT 5.1; ru; rv:1.9.2.9) Gecko/20100824 Firefox/3.6.9 Browser client XHR failure encountered. (age: 1606) Diagnostic info: s: {}, statusCode: undefined, responseText: