Many people find themselves very confused when in the library, while roaming around in Hogwarts. They will often find a yellow arrow, from one of the detectors, which leads them to believe there is a gold brick somewhere in the library. This is not the case. This is a small bug which means the arrow is coming from the Crest Detector, not the Gold Brick detector as you would naturally assume. If you turn off the Crest Detector while roaming around Hogwarts, (as you only need it during the levels), this arrow will disappear and you will not be mislead into thinking you are missing a gold brick.
I have come across another small bug while playing this game, but only once, and I have no idea what caused it. While playing through a level I noticed that player 2, controlled by the computer, had fallen into synch with me. Everything I did, the computer did. It was like having an annoying shadow. I paused the game and then found that “drop out” had appeared in the pause menu. This should only be there when you are playing in coop, and i clearly wasn’t. Anyway, I clicked it, thinking that it might take me out of synch with the computer and it did. However, in the confusion I became player 2, with player 1 flashing it’s usual “Press start to join” message. I have no idea how this happened, and it doesn’t cause any problems, but it is indeed an odd one.