Yes, that was slightly weird. I guess they though it just worked better in the scenes to have them in their new places. For instance (without give to much away), when the 'Buckbeak bit' happened, it worked better for them to be able to run up a hill afterwards than to just run across a field, if you know what I mean (which you probably don't :P ). But it was still a little weird <_<
IMO it wasn't that bad, although it was a little cheesy.
Still, great film though :D