I believe that was the original title of the movie, I have an old cinefantastique with a behind the scenes story of "Dark Angel" perhaps they are trying to fool fans of the Jessica Alba tv show into watching.
On a side note this film has one of the greatest lines ever in a movie. At the end of the movie the big alien guy holds Dolph in submission about to deliver a death blow and says, "I win!" To which Dolph replies, "F@#k you SpaceMan!" and shoves something in the aliens neck.