The Stooges work for Whack magazine but the sign on their scooter says "Focus magazine."
The giant cigar Curly is holding changes from his left hand to right hand between shots.
During Curly's oyster soup scene there are several obvious jump cuts.
Curly is in the radio playing a multi-trumpet instrument. Next scene he has a cymbal held onto his head with some cloth which he didn't have in the previous scene.
The cap Curly wears during the wine tasting has the tassels misaligned before the first sip. Afterward, the tassels are evenly located over both ears.
When Curly takes the harmonica out of his mouth, the music can still be heard playing.
When Moe and Larry are saying "Heave! Ho!" to Curly, Moe almost starts to laugh.
At the 3 minute mark Curly shows Moe his oversized pocket watch and says it's 10 minutes to 4. It clearly shows 1:20.
When Moe and Larry's shorts fall down when the ray gun shoots them, you can see the wires pulling them off.
At the end when they are being taken away hanging on the soldier's bayonets, the wires holding them up can be seen.
When Curly shoots the gun at the bowl of oyster soup, the beer bottle falls over. Should it have been shattered due to the gunshots?