Continuity mistake: In one scene, Zane disturbs a lecture on terraforming at JPL and gets thrown out by security guards. Later on in the movie, somewhere in a Mexican bar, Zane and Ilana are discussing global warming. In a flashback Zane remembers the lecture at JPL. Strange thing, however, he can even remember a part of the lecture which was given at a time when he had already been thrown out.
Continuity mistake: At one point Charlie Sheen is trying to get into a certain facility and is stopped by security. The guard puts his clipboard on top of the car while they talk. When Sheen kicks the car into reverse to run through the hedges the clipboard has disappeared.
Continuity mistake: Near the end, when Charlie Sheen is in a room trying to program stuff, he blocks off the door with an axe so no one can get in. When the van breaks the door, watch the head of the axe - it hits the floor, but mysteriously pops up and goes towards Charlie to miss him by an inch or two.
Continuity mistake: When Zane is climbing the radio dish at the end of the movie his shoes and left sock come flying off. In the very next shot for a brief second you can see his sock is miraculously back on his foot, until he finally gets to the top when the sock is now removed again. (01:46:35)
Other mistake: The power is cut to the satellite facility near the end, but Sheen manages to raise a powered window curtain to look outside.
Revealing mistake: The shot of a computer showing declination (with red numbers moving) at the Oro Array is used twice, despite being two different computers in two different buildings. It is the exact same shot repeated.
Factual error: At the Oro Array, the breakers are turned off because the power is cut. When the alien cuts the cables to the computers, sparks fly out as if there is power.
Revealing mistake: When Kiki's legs "reverse" at the end of the film as he runs off, watch closely. It is clear the effect was achieved through some shoddy image-manipulation. His clothing and hands "warp" slightly a few times around his legs.
Factual error: When Charlie observes the taxi driver at the gate to the facility, he sneaks in by stowing away in the front of the Volkswagen Bug. The luggage space in a bug is barely enough room for a child, plus there is no inner latch release, or handle to close the door.