Corrected entry: They are so advanced they can miniaturize anything but have to use primitive morse code to contact the outside world.
Corrected entry: When a crew member of the miniaturised submarine is eaten by the blood cells, the fact that his atoms will return to full size at the same time as the rest of the crew and the submarine (which provides the suspense, such as it is) is completely ignored.
Correction: It is made clear in the book and the movie that the molecules/or atoms ARE NOT shrunk the space between them is reduced - anything left behind would be absorbed by the immune system one atom or molecule at a time.
Corrected entry: By the end of the film all the crew members are brought to lifesize again. However, nothing is being told about what happens to the submarine.
Correction: It was eaten by the white blood cells, just like they showed happening to the villain.
Correction: This isn't a mistake just because they use a different form of communication.
Bishop73