Audio problem: Clark listens to his father and Earl talking in the hospital through the visitor window. The sound is the same volume and quality as when Earl was using the microphone, which he is not using now. Even if Clark used super-hearing to eavesdrop, it wouldn't sound the same as the microphone. (00:18:35)
Audio problem: When Mr. Luthor was buying the corn field from the farmer he says: 'Now, where do I sign?' The farmer replies: 'Right here Mr. Luthor' and points at the contract. Even though we can only see a profile shot of the farmer as he says these words it is pretty obvious that his mouth isn't moving.
Audio problem: In the beginning of the episode, Clark leaves for the Talon to meet with Pete. He is offered a ride by his mother, but says he'll run there instead. As he closes the door behind him, we hear the sound of him taking off in super-speed, but we can still see him through the glass in the door moving down the stairs in normal speed.
Audio problem: Near the end, when Clark is surprised by the woman coming to say good bye, as he is working on the tractor the distinct sound effect heard is that of a ratchet wrench, but what he puts down is a normal wrench, not a ratchet wrench.
Vortex (2) - S2-E1
Audio problem: When Lex talks to Clark, Clark clicks his flashlight on, and you hear the click signifying he has turned it on. But in the next shot, the flashlight is now off, without another click sound heard to signify that the flashlight was turned off.
Audio problem: As the band is playing right before Clark and Lois enter the prom, the drums are not synced with the music.
Audio problem: After Clark asks Lana to have dinner with him, and she says it's not such a good idea, the camera shot changes so that Lana is on the right side of the shot. In that shot Lana's mouth is moving like she is talking to Clark only you don't hear what she is saying.
Audio problem: After Ryan collapses at Lex's, he and Clark are talking while Ryan is in the hospital. In the shot of Clark as Ryan says "I know what's wrong with me." Ryan's mouth is visible and you can see that he is not speaking the line as we hear it.
Audio problem: Sean drops frozen Jenna and she shatters. He then manages to casually walk out of the room over her without crunching any of the ice. (00:17:30)
Audio problem: Clark is upset over the death of Alicia and is in the barn loft bouncing a ball off the wall. His parents come up and Jonathan sits next to him and tells him that what happened was not Clark's fault. The very next shot shows Martha sitting down and you hear Clark throw the ball again but you can see that his hands never make and motion to correspond with that action.
Audio problem: Just before Adam says "If I read something in out friendship that wasn't there." the camera shot is focused on Lana but you can see Adam's mouth in the top left of the frame. In that shot you can see Adam's mouth is saying the line before we hear it.
Audio problem: After Clark is dumped into the blast furnace and the thieves make a getaway in their truck, you can hear the sound of an accelerating engine as it's driving away, but the brake lights are on.
Audio problem: When Clark talks with Lex in the house where he found the two dead bodies,just after Lex finished his phone call, Clark says to Lex, "You looked at me straight in the eyes and told me she was dead," and then the shot changes to Lex. Clark's lips are still moving even though his line is over.
Audio problem: When Noir-Lois comes out to sing, the microphone picks up her voice before she's anywhere close enough for it to do so. (00:52:30)
Audio problem: Clark says "What if it's some sort of high tech crop duster or something?". Pete replies with "She'll never let us live it down." After the shot changes you can see Pete's mouth say "live it down" again with no sound coming out.
Audio problem: When Sean flags down Whitney's truck, we hear his brakes squeal as he slams on the pedal. A few quick cuts later we see him do the same thing, apparently for the first time. (00:33:25)
Audio problem: When Clark and Manhunter are in his Barn talking about how to stop Bizarro and figuring out the yellow sun can heal Clark, there is a beep of a watch or someting similar in the background, but neither Clark nor the Manhunter react to it, which means it happened off screen and unintentionally.
Audio problem: After they get the spaceship into Pete's shed, Pete wants to go tell Chloe. Clark insists that he doesn't and Pete says "To her, this thing is the Holy Grail.". The shot zooms in and Pete's mouth shows him saying "Holy Grail" again even though he already said it and you don't hear the words.
Answer: The kryptonite only creates mutations when it reacts with the environment and an individual. Remember, the FDA and several environmental groups did check out Smallville after the meteor shower, but found no danger in the rocks. Obviously they're not always emitting mutating rays, or all the flora and fauna of the surrounding area would be horribly mutated.
Phoenix