I noticed this the other day and again today - the live flight tracker seems to be displaying old flights.

As I am flying EHAM-EGPH today, I still see Chris and Joe' flights listed there, although on the front page it says 1 pilot online.

I've had a look at this but it's not really my area of expertise so I've referred it to Chris H. Unfortunately he is dealing with a computer malfunction on a real aircraft at the moment, so it might be a while before he can take a more detailed look.

Whoops, fixed it!
I altered one of the settings during some testing I was doing and forgot to set it back!
Normal service has been resumed!