Multi part file upload not working in firefox 36.which works fine in other browsers and previous versions of firefox

I am using Ajax calls for transferring file in multi part Post message in 10 mb chunks for every Rest call going to server. It was working fine in other browsers but in latest version of Firefox 36 the ajaxcalls get rejected by the browser. But works fine if I set the chunck size to 4 kb. I cant find root cause. Any help is appreciated.