I and various other resident gurus have already made our position clear.
Don't come running to Computers & Internet looking for tea & sympathy (or just tech support) if you are running XP beyond D-Day.
Its time to stop clinging on to XP and move on.
Seriously, we're not telling people that to piss them off, we're not telling people that because we're somehow beholden to Microsoft... we're telling people this because we know what home users are like with the state of their PCs, because we've seen this all before with Windows 2000, Windows NT, Windows 95, because we know its going to be a lot worse with XP, because we know people just won't begin to comprehend the security consequences of their stubborn actions, they don't comprehend that all software (including anti-virus etc.) is reliant on APIs provided by at the OS level by Microsoft and don't comprehend the security risks (and system stability risks) of the OS being left to grow cobwebs.
In the mean time, this...
Is it because I've disabled some 3rd party cookies which install themselves as soon as one visits PPRuNe?
Seems more likely to be the cause of your grief.
Don't mess with cookies or javascript unless you understand the consequences of your actions.