Audio problem: When Frankenstein first opens the door to the monster-making room, the rusted handle breaks into two pieces, but when he throws them down, only one piece can be heard hitting the floor. (00:28:15)
Audio problem: As Frankenstein lures the monster back to the castle with the violin, if you watch very carefully, some of his bow movements don't match the length of the sound that is heard. (01:35:30)
Audio problem: When the monster is climbing up the laboratory steps following the music Frau Blucher is playing on the violin, she says, "Your grandfather would play this music for the creature he was making", her mouth does not move.
Audio problem: When Frederick is playing darts with Inspector Kemp, the last dart that Frederick holds flies backwards when he raises his arm quickly causing the dart to land on the floor, but when he throws his now empty hand forward, the sound of the window breaking is heard.
Audio problem: When they first find the monster conscious, Frederick says "Is the sedative ready?" The reply, "Yes, doctor," comes from Frau Blucher, who isn't there, and doesn't make another appearance in the film until she releases the monster and he escapes. It should've been either Inga or Igor saying it.
Audio problem: When the Monster is tap-dancing to "Puttin' on the Ritz", the motion of his legs and feet do not correspond to the sound of the tap-dancing.
Audio problem: At the end of the movie when The Monster is shaking hands with Inspector Kemp, he pulls his prosthetic arm off. Inspector Kemp is heard saying, "Oh shit," however his mouth says just "Oh."
Chosen answer: While no specific date is given, Mel Brooks wanted to do a tribute parody to the classic 1930's horror film, thus the Black and White film and the 30's style film techniques. However, Hans Delbrück (the brain Igor is suppose to steal) was a real-life person who died in 1929. Given that and the cars seen, it's a safe bet it's suppose to be set in the early 1930's.
Bishop73