bit-tech.net reports:
"As can be seen in this video by YouTube user, themikepotter, the bug appears to cause Altair's animation to literally freeze – even if he's in the middle of the air or galloping along the ground. Mike isn't alone, either. This problem has resulted in plenty of PS3 owners whipping out their cameras and uploading the footage to sites like YouTube, but so far nothing from Xbox 360 gamers."