Right before the scene where the three soldiers confront the aliens, they climb through a fence, breaking it. According to the Directors Commentary, Jonathan Morgan had to pay for repair of the fence. (The fence is seen earlier in the movie, already in it's broken state, in the scenes with the UFO)
Ten people were supposed to show up to play various roles in the movie, but they didn't show up. This is why Anthony Crane plays so many parts.
Shanna McCullough did not show up when the scenes at the beginning (in the UFO) were shot, that is why Anthony Crane takes the part (played for comedic effect), until the first outside shot.
Director Jonathan Morgan had to get permission to use the stock footage of the Flying Saucers used in this movie.
Actress Serenity says in the DVD Commentary that she did research into the way women acted old "B movies" - this is why she holds her hands out whenever her scientist character asks a question.