sphinxsearch returns "failed to send client protocol version"

On some of my servers, doing a sphinx php query returns that error. Searching google I can't find anything except this is part of why the error came out: ``` // send my version // this is a subtle part. we must do it before (!) reading back from searchd. // because otherwise under some conditions (reported on FreeBSD for instance) // TCP stack could throttle write-write-read pattern because of Nagle. if (!$this->Send($fp, pack('N', 1), 4)) { fclose($fp); $this->error = 'failed to send client protocol version'; return false; } ``` The close I've found is this http://www.sphinxsearch.com/forum/view.html?id=4919 But I do not know where the sphinxapi.php is (I installed using manual compile) and not sure if that's a good idea. Anyone has any idea?