Old summary/body version in edit form

I just had the weirdest thing in #1710850: Deploy RestWS for D7 project issue JSON

I updated the summary at 21:00

21:27 Still old version when I refresh the page

Worse when trying to edit again... old version as base
21:31 saved bad/old version of summary

Compare works... my work was saved : https://drupal.org/node/1710850/revisions/view/6684903/6686027

21:34 restored my new summary by copy pasting
21:37 Another summary edit, now shows up OK

PS: no messing with webservices here, just plain clicking in Firefox ;) The only other unstable component I can think of is Dreditor (latest 1.x).