Just in from REG (with thanks also to Joan and Ruth – from the Shooting Star Charity – for coming to this conclusion from a different angle):

I will not be able to attend the Shooting Star gala in may as I will be filming Wah-Wah in Swaziland. We start filming at the end of April.
Cheers
Richard

Obviously the event will still be worth attending as there will be plenty of other celebrities there. The charity itself is one that is near and dear to REG’s heart, so he’ll be there in “spirit” even though he can’t physically make it to the event itself.

Thanks to REG, Ruth and Joan for the update.