IP Camera Viewer IIOException: No SOF segment in stream

I am using ACTi cameras and the ones that are run PoE work fine, but the coax cameras via encoder work for about 30seconds and then gives the IIOException. Any ideas as to what I can do to remedy this?
The URL i am using is http://10.170.133.11:80/cgi-bin/encoder?USER=XXXX&PWD=XXXX&CHANNEL=6&STREAM=2&GET_STREAM