Other mistake: Stripe manages to get the TVs and video camera working in the department store even though Kate hadn't turned the power on yet.
Other mistake: In the bar, one Gremlin is changing the music selection on the radio. However, the tuning knob is on the right side, out of his reach, the tuner doesn't move, but the music style changes.
Other mistake: When the gremlin is using live wires to manipulate the traffic lights, the smoke goes in reverse, indicating a reverse footage shot. (01:05:55)
Other mistake: Rand demonstrates the supposedly new razor attachment on the Bathroom Buddy. However, it was already on the device in the beginning.
Other mistake: One of the evil Gremlins is messing with a stoplight by shorting out wires. The result is a very bright spark. Bright light is supposed to have a negative effect on the Gremlins - when we see them hit by the headlight beams in the bar they scream.
Answer: The original film was released before the PG-13 rating existed (it was one of the films responsible for its creation). Producers decided to remove some of the language and violence for the DVD release to avoid complaints about the PG rating.