At the end of the movie when Edwina is dancing she puts her feet on top of Rogers. She is wearing ballet type slippers. When Edwina and Roger are dancing a few second after Edwina is wearing high heel shoes.
Roger has a watch on when he arrives at Edwina's wake but loses it when he falls asleep and when Terry wakes him up, he has to ask her what time it is. He gets it back in the next scene, however, when he and Terry get in bed.
When Edwina (through Roger) declares that Terry needs a spanking and she happily consents, her derriere is already red from previous takes.
After Edwina enters Roger's body and they use the bathroom for the first time, behind Edwina you see stalls. Behind Roger you see a wall. You should be seeing the same thing since he's looking into a mirror.
Several of the backgrounds while Roger and Edwina are talking into the mirror do not match. They should be identical.