Jetpack can't connect : statistics

Hello,
we upgraded to 4.3.1 yesterday (including plugins and themes). The site is a multisite with 1100 blogs. At the moment, none of them can see their statistics. My blog c3iq.our.dmu.ac.uk get a spinning wheel. The main blog our.dmu.ac.uk complained that it needed reconnecting to Jetpack. On doing this stats work again but only have stats for the last two days. I went to the debug page on my blog for it to say :

There seems to be a problem with your site’s ability to communicate with Jetpack!

I had a look with ngrep to see this:

T 10.2.224.4:55119 -> 192.0.78.27:80 [AP]
  POST /xmlrpc.php?for=jetpack&wpcom_blog_id=19634228 HTTP/1.0..User-Agent: WordPress/4.3.1; http://c3iq.our.dmu.ac.uk..Host: jetpack.wordpress.com..Accept: */*..Authorization: X_J
  ETPACK token="xxxxxxxxxxxxxxxxxx" timestamp="1442999727" nonce="xxxxxxxxxxxxxxx" body-hash="xxxxxxxxxxxxxxxxxxxxx" signature="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" ve
  rsion="3.7"..Accept-Encoding: deflate;q=1.0, compress;q=0.5, gzip;q=0.5..Content-Length: 257..Content-Type: application/x-www-form-urlencoded....<?xml version="1.0"?>.<methodCall
  >.<methodName>jetpack.fetchSiteOptions</methodName>.<params>.<param><value><array><data>.  <value><string>siteurl</string></value>.  <value><string>home</string></value>.</data><
  /array></value></param>.</params></methodCall>                                                                                                                                    

T 192.0.78.26:443 -> 10.2.224.4:52869 [A]
  ......                                                                                                                                                                            

T 192.0.78.27:80 -> 10.2.224.4:55119 [AP]
  HTTP/1.0 200 OK..Server: nginx..Date: Wed, 23 Sep 2015 09:15:27 GMT..Content-Type: text/xml; charset=UTF-8..X-hacker: If you're reading this, you should visit automattic.com/jobs
   and apply to join the fun, mention this header...X-ac: 3.lhr _dca..Content-Length: 367..Age: 2..Via: 1.1 localhost.localdomain....<?xml version="1.0" encoding="UTF-8"?>.<methodR
  esponse>.  <params>.    <param>.      <value>.      <struct>.  <member><name>siteurl</name><value><string>http://c3iq.our.dmu.ac.uk</string></value></member>.  <member><name>home
  </name><value><string>http://c3iq.our.dmu.ac.uk</string></value></member>.</struct>.      </value>.    </param>.  </params>.</methodResponse>.                                    

T 10.2.224.4:55120 -> 192.0.78.27:80 [AP]
  GET /jetpack.testsite/1/?url=http://c3iq.our.dmu.ac.uk/xmlrpc.php HTTP/1.0..User-Agent: WordPress/4.3.1; http://c3iq.our.dmu.ac.uk..Host: jetpack.wordpress.com..Accept: */*..Acce
  pt-Encoding: deflate;q=1.0, compress;q=0.5, gzip;q=0.5....                                                                                                                        

T 10.2.224.5:80 -> 94.102.51.15:51893 [AP]
  HTTP/1.1 200 OK..Date: Wed, 23 Sep 2015 09:15:23 GMT..Server: Apache..X-Powered-By: PHP/5.4.38..Connection: close..Content-Length: 370..Content-Type: text/xml; charset=UTF-8....<
  ?xml version="1.0" encoding="UTF-8"?>.<methodResponse>.  <fault>.    <value>.      <struct>.        <member>.          <name>faultCode</name>.          <value><int>0</int></value
  >.        </member>.        <member>.          <name>faultString</name>.          <value><string></string></value>.        </member>.      </struct>.    </value>.  </fault>.</met
  hodResponse>.

I have ‘x’ed out anything that looks like a security string.

Any help please?

Best regards.

https://wordpress.org/plugins/jetpack/