Continuity mistake: When the people are dancing to the music in the clubhouse, in the background we can see Fred and Ernie chatting to two girls by the bar, and there is a girl in a blue dress standing by Fred. But in the next shot, she has changed position and is now standing behind him.
Audio problem: When the stripper puts her foot on Ernie's leg during the dance sequence at the bar, you can hear Jack Douglas' voice, but his mouth does not move.