In Harry Potter and the Deathly Hallows Part 1 in the beginning of the movie, Harry is taken to the Weasley's house, which is protected by a magical barrier that we clearly see when Harry and Hagrid go through in Hagrid's motorcycle.
Later in the movie, in the wedding scene, the death eaters started attacking the place. How were they able to go through the barrier? In the part 2 film, they were vaporized if they tried to go through and they took a long time to destroy it, good ol'Voldy had to come with all his power and destroy the barrier himself.
How did they manage to go through this one?