[HPFGU-Movie] filming of HBP and 'Jack'??

[Valerie Flowe]

In reading through the many, many Equus reviews (I never get tired of 
folks praising Dan & Richard Griffiths performances!), I'm curious 
about something. Equus runs through June 9th. Then one source stated 
that Dan is filming 'My Boy Jack' till September. Another source said 
he's starting to film HBP this summer. How can  he film 2 productions 
at once? And when does the poor boy get a vacation!?
Plus you know he'll be swamped with interviews in July when the final 
book and OotP comes out! Hope he doesn't burn himself out!
Anyone know for sure when HBP starts filming?
Valerie