For two years now, everyone in the English-speaking world has called the fourth Professor Layton game Professor Layton and the Specter's Flute. That's what the Japanese title is, anyway.
The Professor Layton people announced last month that they are releasing this game, under the title Professor Layton and the Last Specter, because they want to confuse all their fans. However, this month, they just announced that this game will be released as Professor Layton and the Spectre's Call in the UK.
They did the same sort of thing with the second game, Professor Layton and the Devil's Box, which was retitled Professor Layton and the Diabolical Box and Professor Layton and Pandora's Box. Anyone who's played the game will tell you that all three of those titles have nothing to do with the game at all. In the game, it's actually called the Elysian Box.
In conclusion, the titles for the Layton series are weird, and it would be easier if all the games had only one title.
Meanwhile, the only game in the series which desperately needs a new title, Professor Layton and the Mask of Miracle, has not yet been changed.