I'm sure there is a reason, but without knowing what version & update level
of PPt, how you're going about it & exactly what "won't let me" means to you
it's a little difficult to pinpoint what that reason is.
As a guess, however, it may be that you're actually attempting to Group the
photo with a Placeholder, not a Text Box. Title, SubTitle, Bulleted List &
Content Placeholders cannot be grouped with other objects. IOW, basic rule
of thumb: If it's a part of the slide's layout when you add the slide it
can't be grouped - even with like objects.
If that isn't the problem please supply the info requested above as well as
details about the actual picture file type, how it was inserted & anything
else about the specific objects you're trying to Group.
Regards |:>)
Bob Jones
[MVP] Office:Mac