I have seen an article about having to close a FPL after arriving in the UK in either Flyer or Today's Pilot - trustworthy magazines in my opinion. And I just found this on the internet, which states basically the same thing:
http://www.modernpilot.com/index.php...=124&Itemid=55
It seems to me that the UK is different from other EU countries in that they do not automatically send an ARR message/close a FPL upon arrival, where other countries do. But I asked my questions on this forum because I want to be sure... :-)