Shy - great tip about hitting quote to see the link - I have been having this problem with my browser for ages.
This is a well known pprune problem and fix (reply). I seemed to fix mine by resetting the pprune cookies.
It went something like:-
Turning down/off ad blocker
Making sure cookies were enabled
Closing pprune
Clearing pprune cookies (will delete saved password)
loading pprune
logging on (needs password)
accepting cookies
Turning up/on ad blocker