Continuity mistake: At one point before Obi-Wan and Qui-Gon fight Darth Maul, Anakin stands up in the fighter he's in, Artoo's nozzle thing is on the wrong side of his dome, then it switches back to the right side the next time we see him.
Continuity mistake: In the Trade Federation spaceship, when Obi-Wan and Qui-Gon jumps from the ventilation shaft to the hangar, everything changes in the next shot. The boxes are different, Obi-Wan is closer to Qui-Gon, they are closer to the edge of the wall and the wall itself is different.
Continuity mistake: When they quit the spaceship to go to Mos Espa, R2-D2 has a metal bar retaining his rear legs. He doesn't have this in the rest of the film.
Audio problem: When Anakin is working on his Pod and his friends show up, you hear them laughing. When they leave, if you listen carefully, you can hear that the soundtrack used for laughter when they first showed up is played again. (00:45:50)
Continuity mistake: When the battle droids first walk through the Gungan shield you see the Gungans throwing hundreds of boomas at the droids but in the wide shots of all of the droids not many droids have been hit and you can't see any boomas on the ground.
Continuity mistake: In the shot where Obi-Wan is looking up at Qui-Gon and Darth Maul, there are several vertical beams on the right side of the walkway. In the previous shots, the beams were on the left side. When Obi-Wan lands on the walkway after jumping up, the beams are again on the correct side.
Continuity mistake: When Jar Jar is arrested, he and Obi-Wan switch position after the second shot of them. Also, Captain Tarpals has moved to the other side of them. (00:14:05)
Revealing mistake: During the second lap of the Podrace, the announcer says, "Skywalker's spinning out of control" and there's a shot of the audience. After Anakin has won the race, the same shot is used again. This can be seen, for example, from that the people on the steps make the exact same movements in each shot. (01:01:50 - 01:06:50)
Audio problem: When Anakin and Qui-Gon are running to Amidala's ship, Anakin says, "Qui-Gon sir, wait, I'm tired" but his lips hardly move when he says this. (01:13:35)
Continuity mistake: The screen that Shmi Skywalker holds in the podrace changes shape between shots. (00:58:45 - 01:00:35)
Continuity mistake: When Obi-Wan kills Darth Maul, he grabs Qui-Gon's lightsaber with his left hand. But when he twists above Maul's head, he's holding it in his right hand. In the next shot, it's back in his left hand. (01:59:10)
Continuity mistake: When the queen's ship lands on Tatooine you can see that there aren't very many big rocks near the ship but later when Panaka and Obi-Wan are talking about the storm they pass a row of rocks that wasn't there before.
Continuity mistake: Before the pod race begins, as Jabba the Hutt says, "Welcome.", the woman to his right has her hand on the wall. In the next shot, she is no longer touching the wall and her head is turned in a different direction. (01:56:00)
Continuity mistake: During dinner, as Anakin says, "I had a dream I was a Jedi", his arms are on the table. In the next shot, they're off the table, and there's a piece of cutlery in his food bowl, which wasn't there in the previous shot. (00:40:25)
Audio problem: After the control ship blows up, one of the pilots says, "Look, one of ours out of the main hall." His lips continue to say "way" (as in hallway) but the sound is cut off.
Audio problem: When Obi-Wan and Darth Maul are fighting, after the second time Maul swing his lightsaber over Obi-Wan's head, their lightsabers make contact three times, but there are four clashing sounds. (01:56:35)
Continuity mistake: During the battle in the hangar, the Droidikas roll out and stop near the ship exit, but when the Jedis ignite their lightsabers, we see the droids are missing in the background.
Continuity mistake: When Jar Jar goes to retrieve the wrench that he dropped in the engine of Anakin's podracer, he moves his hand towards the upper part of the engine. In the next shot, he sticks his hand into the middle of the engine. In the following shots, his hand remains in the middle, but when he says that he's stuck, his hand is once again in the upper part. (00:46:45)
Continuity mistake: Right after Anakin blows up the generators on the droid control ship and he is flying out of the hanger you can see a close up of R2, his lens is on the wrong side.
Audio problem: Where Natalie Portman and some of the security detail are fighting in the Palace corridors, her shiny weapon makes a distinct noise and the normal blasters makes a different sound. Later, she is given a regular blaster to get up the outside of the Palace. However, when she fires that gun to break the window they've ascended to, it makes the same noise as her shiny blaster, not the sound of a normal blaster. (01:50:31)
Chosen answer: According to "Inside the Worlds of Star Wars: Episode I" by Kristin Lund, they are "laser doors which lock into position in response to potentially lethal power outputs that occur intermittently during plasma activation process" (the fight takes place in a plasma energy processing plant). There are six laser doors in deference to an ancient Naboo legend in which Chaos is held back by six inpentrable gates. As you say though, they're really just a plot device to add dramatic tension to the duel!
Sierra1 ★