impossible to stop bucket compaction, UI errors - Invalid post received: / errMsg: Object Not Found, statusCode: 404,

build 1645
1.2 buckets with > 1M docs in each
2. rebalance in 1 node
3. start bucket compaction during rebalancing and then try to cancel compaction that is running

click Cancel throws errors and compaction continues

Invalid post received: {mochiweb_request,#Port<0.604431>,'POST',"/undefined",
{1,1},
{16,
{"host",
{'Host',"10.5.2.11:8091"},
{"connection",
{'Connection',"keep-alive"},
{"authorization",
{'Authorization',
"Basic QWRtaW5pc3RyYXRvcjpwYXNzd29yZA=="},
{"accept",
{'Accept',"*/*"},
nil,
{"accept-encoding",
{'Accept-Encoding',"gzip,deflate,sdch"},
{"accept-charset",
{'Accept-Charset',
"ISO-8859-1,utf-8;q=0.7,*;q=0.3"},
nil,nil},
{"accept-language",
{'Accept-Language',"en-US,en;q=0.8"},
nil,nil}}},
{"cache-control",
{'Cache-Control',"no-cache"},
nil,nil}},
{"content-length",
{'Content-Length',"0"},
nil,
{"cookie",
{'Cookie',
"randomKey=test_docs-102410; ri=1346114197055; auth=QWRtaW5pc3RyYXRvcjpwYXNzd29yZA%3D%3D"},
nil,nil}}},
{"origin",
{"Origin","http://10.5.2.11:8091"},
{"invalid-auth-response",
{"invalid-auth-response","on"},
nil,nil},
{"x-requested-with",
{"X-Requested-With","XMLHttpRequest"},
{"pragma",
{'Pragma',"no-cache"},
nil,
{"user-agent",
{'User-Agent',
"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.81 Safari/537.1"},
{"referer",
{'Referer',
"http://10.5.2.11:8091/index.html"},
nil,nil},
nil}},
nil}}}}}



Client-side error-report for user "Administrator" on node 'ns_1@10.5.2.11':
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.81 Safari/537.1
Browser client XHR failure encountered. (age: 1136) Diagnostic info:
s: {"url":"undefined","isLocal":false,"global":true,"type":"POST","contentType":"application/x-www-form-urlencoded","processData":true,"async":true,"accepts":{"xml":"application/xml, text/xml","html":"text/html","text":"text/plain","json":"application/json, text/javascript","*":"*/*","script":"text/javascript, application/javascript, application/ecmascript, application/x-ecmascript"},"contents":{"xml":{},"html":{},"json":{},"script":{}},"responseFields":{"xml":"responseXML","text":"responseText"},"converters":{"text html":true},"jsonp":"callback","timeout":30000,"cache":false,"dataTypes":["text"],"crossDomain":false,"hasContent":true}
xhrStatus: error,
xhrReadyState: 4,
errMsg: Object Not Found,
statusCode: 404,
responseText:
Not found.