Visible crew/equipment: After taking the enzyme, Mckay is talking to himself as he dials the gate. When he goes to push the centre button, an arm moves on the opposite side of the DHD. (00:09:35)
Character mistake: Rodney says that one hour in real time would give them months inside the field. This is incorrect because if the ratio of time were 1:250 as stated before, one hour would only convert to 250 hours, which is 10 days and 10 hours.
Continuity mistake: In the scene where Michael is first introduced to his quarters, he goes to pick up a picture of his parents. In the first shot, the laptop next to the picture is closed, but in the next shot through the security camera, the laptop is wide open.
Revealing mistake: When they are escaping in the beginning of the episode, watch Rodney dial. As he finishes, one of the DHD address panels pops out and falls off.
Continuity mistake: During the episode Ronon has flashbacks and keeps referring to "the gate" when trying to make his wife leave. It was only after Ronon met the team from Atlantis he begun using the term Stargate as most (if not all) prople in Pegasus refer to the Stargate as the ring of the ancestors.
Revealing mistake: One of the dots used to "steady" the CG within a shot remains in the shot for a protracted period of time. Its a blue dot towards the bottom right of the screen. (00:17:55)
Audio problem: McKay is talking to Sheppard about the differences between himself and Rod, and at one point says that maybe Rod screwed up and was chosen for "a one-way ticket to another universe", yet his lips form the word 'galaxy'.
Continuity mistake: When the Atlantis team finds out that the experiment has caused problems in another universe, McKay's sister says to Rodney, something like,"You said that the chances of connecting to another universe that was inhabited were astronomically small." It was in fact Carter that said that.
Character mistake: General Landry says that the Asurans would need to rewrite McKay's macro to gate to any planet in the Milky Way. In fact they wouldn't have to bother with the macro, because they could simply gate directly to the Milky Way from a ZPM-powered Atlantis.
Continuity mistake: Lt. Colonel John Sheppard is packing his belongings up and his skateboard is against the wall at first, then it is on top of boxes.
Character mistake: It is mentioned the previous solar flare was 15000 years ago, and Shepard says that the ancients were in the middle of a war with the wraiths, but as stated in previous episodes the war lasted 200 years and ended 10000 years ago. (00:31:30 - 00:38:10)
Character mistake: In the first few moments of the episode, as the survey team walks through the halls, the German member of the team is wearing his flag patch upside-down.
Continuity mistake: After returning from the Daedalus, McKay talks to Nola about how he had been a god to them the past years. In the shots filmed from his front, the standard radio headset is visible in his ear. In the shots from behind, it is gone.
Continuity mistake: In several scenes (mostly on the planet) we see characters reacting to tactical information from the oracle as if it's displayed in real time. However, the units in the display are moving far more quickly than they could in real-time.
Quarantine - S4-E13
Revealing mistake: When Dr. Zelenka drops into the room from the ceiling vent, the wall with the monitor projecting the map of Atlantis vibrates as he hits the floor. (00:38:00)
Factual error: When Sam breaks her leg, Dr. Keller discusses with McKay the possibility of internal bleeding, then returns to splint her leg and offer her some ibuprofen for pain. A doctor concerned about internal bleeding would never offer a patient ibuprofen, as it inhibits blood clotting.
Deliberate mistake: As the Wraith "stun bomb" activates at the SGC and everyone falls to the ground, it is visible how everyone uses their arms to dampen the fall.
Continuity mistake: When the Wraith have taken over the Daedalus, Dr. Keller's hair changes from being wavy to being completely straight and back to wavy.
Other mistake: McKay and Jackson enters a room and runs into 2 armored figures, Jackson eventually reveals that they are empty suits, however in every shot shot from behind the suits, the suits are constantly moving, as if they are hanging on strings.
Answer: Because even all 4 Naquadah generators (one was destroyed) together is only enough to dial Earth for approximately 1.2 seconds (As seen in the episode "Letter from Pegasus"). Further, if Earth had found a ZPM, they would dial Atlantis and let them know. After all, the SGC has no other use for a ZPM than to dial Atlantis.
Grumpy Scot