Thanks, didn't know that. I always assumed that having had a re-clearance from the Airways system they would inform your orginal FP destination.
I found out a few years ago when on a flight from Cambridge I'd diverted into Maastricht trying to get to Spa. Cambridge called me on my mobile, saying that Brussels was asking what had happened to me. I too found it a bit odd, as the diversion had required a reclearance from Brussels Control.