Audio problem: When Jay goes to join MIB, he greets the security guard with "'sup pops?" without moving his lips. (00:33:40)
Audio problem: When Will Smith is looking at the two space ships at the MIB headquarters, if you look in the background Zed and K are there typing on the computer. But if you look closer you can tell that they're not even touching the keyboard and the sounds are just added into the movie. (01:16:00)
Answer: The person in question is actor/comedian David Cross. In the first MIB film, Cross is listed in the credits as "Morgue Attendant," and he ends up glued to the morgue ceiling, presumably killed by The Bug. If he had survived, the Men in Black would have certainly neuralized him, anyway, and he would have no memory of the alien encounter or the Men in Black. In MIB 2, David Cross is listed as "Newton" (the video store nerd) who apparently recognizes K, because K had asked Newton to reserve a videotape for him at some time in the past. K made this video request before he ever met J, and then K neuralized himself after leaving a trail of clues leading to the video store. Newton remembers K, so Newton hasn't been neuralized in years. Therefore, Newton in MIB2 cannot be the same character as the Morgue Attendant in MIB.
Jazetopher