Other mistake: At the beginning, when everyone is watching Shelby fighting on TV, the timer is going too slow. According to the timer, the fight ends at 2:53, which is only 7 seconds of fighting, yet the fight was way longer than that.

IWanna Stay with Spencer - S1-E5
Other mistake: The "Fan of Hammers" has all the hammers pointed the same way. But when the hammer goes into the wall, it goes in backwards. It is also there through all the rest of the shows and even in season two, where in "iKiss" it has a black handle. (00:02:35)
Other mistake: When the military barge into Nevel's house, Uncle Roger puts the camera down and you can see it not moving whatsoever, but in the shot from the POV of the unmoving camera the shot is moving.
Other mistake: When Carly and Freddie are frantically trying to find a birthday present for Principal Franklin, they are talking in the kitchen and you can see a microwave above the sink. Carly then runs to the counter and grabs a microwave to give to him. Why would they have two?
Suggested correction: There is no visible microwave above the sink it is just a strange looking mirror. Also, some people have microwaves and microwave ovens which is what they gave principal franklin.
Other mistake: There is an A stuck to Carly's butt, but nothing touched Carly's butt when she got downstairs. (00:20:30)
Other mistake: In the theme song opening of iCarly, The Slap is saved under their favorites on their computer. The Slap is Hollywood Arts' website. Why would people living in Seattle go on a school website for a school in Hollywood?
Other mistake: When Carly and Sam are pumping the watermelon full of air, one shot zooms in on Carly's finger as she hits the on-switch. The device is turned off as she removes her finger. (00:01:32)
Other mistake: In one of the episodes, Sam said they've been doing iCarly for 2 years and in another episode Carly said they were in 9th grade which is the first year of high school. So they've been in highschool for 2 years?
Suggested correction: This mistake is too vague if you're not going to indicate which episode the line comes from.