Continuity mistake: When Count Dooku ignites his lightsaber, his arms are up and the saber is pointing right. In the next shot, his arms are down and the saber is pointing left. (00:11:55)
Continuity mistake: When Padmé is waiting for Anakin by the giant column, her position by the column differs between shots, seen from its design. This also happens to both her and Anakin as they're talking. (00:24:40)
Continuity mistake: During the scene where Padmé tells Anakin that she's pregnant, the shadows keep changing between shots.
Continuity mistake: When Anakin and Count Dooku are duelling, as Dooku says, "I sense great fear in you, Skywalker", Anakin's lightsaber is slanted upwards, but in the previous shot, it was slanted downwards. (00:13:00)
Continuity mistake: When Palpatine and Windu are fighting they end up standing stuck face to face with their lightsabers. At first Palpatine's lightsaber is pointing to the right side of Windu. When it cuts to a close-up of Windu Palpatine's lightsaber is pointing to Windu's left. (01:09:05)
Continuity mistake: In the very beginning, Obi-Wan and Anakin are flying near that big republic ship. Notice that it is calm everywhere even under the ship, but in the very next shot their are hundreds of ships and starfighters going by.
Character mistake: In the scene where Mace Windu and the other three Jedi attempt to arrest Palpatine, the first Jedi that Palpatine kills practically has his back turned to him, which is not something a Jedi Knight who is trained to be mindful of his surroundings would do. As we can see in the film, it takes Palpatine several seconds to stand up from his chair, draw out his lightsaber, threaten the Jedi, leap over his desk, and then lunge at them, meaning the Jedi had plenty of reaction time to avoid this.
Continuity mistake: When Palpatine and Anakin, who's carrying Obi-wan, climb through the elevator shaft we see Palpatine put his left hand down pushing himself up. When it cuts he does the same again. (00:15:40)
Continuity mistake: When Anakin visits Padmé before going to Mustafar, as he says, "Have faith, my love." he's touching the side of her head. In the next shot, his fingers change position. (01:25:25)
Continuity mistake: When Yoda is done with the holographic meeting with the rest of the Jedi Council about sending Obi-wan after Grievous, he gets up and walks to the trooper behind him. We also see Chewbacca follow him, stop, and cross his arms. When it cuts to the trooper saying, "The droids have started up their main power generators," we see Chewbacca still walking and stopping, but this time he doesn't cross his arms, he places them on his hips. (00:47:20)
Continuity mistake: After having his nightmare/premonition Anakin wakes up, while Padmé sleeps beside him. The blankets on Padmé and the bed change position in the following shots. (00:29:50)
Continuity mistake: Just as Yoda starts fighting Darth Sidious, Yoda's walking stick disappears from the ground behind him.
Continuity mistake: When Obi-Wan and Anakin are fighting Dooku, Dooku throws Kenobi away. Before he is thrown, his light saber is in his right hand. When we see the shot of him on the ground, it is in his left. It is back in his right hand when he gets up. (00:12:50)
Continuity mistake: When Grievous escapes with the escape pod, three pods launch before his. When his goes off there are no signs of the other three anywhere ahead of him. They didn't didn't have enough time to change direction flying off screen. (00:20:30)
Continuity mistake: In the first shot of the scene where the Jedi Council refuses to give Anakin the rank of Jedi Master, Obi-Wan has both feet on the floor. In the next shot, one leg is crossed over the other. (00:33:35)
Continuity mistake: When Obi-Wan says to General Grevious, "Not this time. And this time you won't escape", you can tell that it is a flipped shot because the moles on Obi-Wan's forehead are the opposite way round to how they are normally.
Revealing mistake: After the battle between Obi-Wan and Anakin/Darth Vader, Vader lies badly burned on the ground slowly crawling up. Palpatine's shuttle flies by, as seen by a shadow. However, even the lava in the shadow turns dark, like the lava is glowing from an external light source instead of glowing within itself. (00:57:50)
Revealing mistake: Computer generated characters that have light sabers (like Yoda) show a glow on them from their sabers when they are on. All "live action" Jedi do not.
Audio problem: When Obi-Wan speaks on R2-D2's radio, the sound editor cut a lot of frequencies, bass and middle, to make it sound like a radio. But when R2-D2 puts the radio in his shell, "magically" there is a lot of low middle in the voice. It does sound like Obi-Wan is talking from inside R2-D2, if it wasn't a radio, but in this case it is and shouldn't sound much at all, when the shell cuts the high frequencies. No low frequencies + No high frequencies = No frequencies. (00:09:40)
Continuity mistake: In the fight scene between Obi-Wan and Grievous, look closely at the lightsabers in Grievous' right hands as he ignites them. The one on top is an Obi-Wan hilt(blue) and the bottom is an Anakin hilt(green). Throughout the fight, these two sabers alternate colors constantly between shots. When Grievous' hand is severed the second time, he drops the Obi-Wan(green) and retains the Anakin(blue).
Answer: Darth Vader has a special chamber in which parts of the suit can be removed for comfort. When he is not in the chamber he must wear it at all times in order to survive.