when Eddie's mom is in his room, when the stereo starts playing and while she's trying to stop it, she lowers every equalizer potentiometer.
When she goes out of the room, the potentiometers are back in their original place.
When Leslie is outside the radio station, she starts counting, "One Mississippi, two Mississippi," etc. By the time she reaches the teens, she has dropped "Mississippi." Also, as she counts, the next numbers she recites are in the low 40's. The next time she is shown, she's at fifty six and seven, and the last time she's shown counting (before ninety) she's back to twenty six and twenty seven.
In the scene where Eddie is doing his laundry and watching a news report, there is a 5 second shot of the TV screen he is looking at. If you look carefully at the left hand side of the screen you can see a reflection of the film crew.
When an LP is played the grooves in the vinyl rotate in a clockwise direction which causes the stylus to travel from the outer edge of the record to the center. In the scene where Eddie is recording Sammi's album to cassette tape (at high speed) the record is rotating anti-clockwise...yet the needle is still travelling towards the center. If the record was turning anti-clockwise the needle would not do this...it would simply move in the opposite direction and fall off the outer edge.