Evo,
My whiskers started quivering when you mentioned the missing action buttons/menu items
Possibly a dead end but consider this: Something came up last week that might be of use. Had a whale of a day logiking (!!!) out why someone couldn't post despite being logged in on PPRuNe and across multiple browsers. There was no post button whichever browser he used!!
Turned out to be a tick box in some privacy/firewall software made by Norton. The box referred to pop ups but it stopped our block graphic reply button appearing throughout his raft of browsers. Might be worth investigating a little further away from your browser.
By the way, anyone who intensively PPRuNes without tabbed windows loading new pages while you read is wasting so much time it's unbelievable
Regards
Rob