When we first see the video tapes falling over (after the first night Homer takes Nappien), we are shown Homer, Marge and Bart watching the tapes fall, but Lisa is nowhere in sight. In the text shot, when the camera pulls back to show that the tapes have been arranged in the shape of Homer's face, Lisa is suddenly between Marge and Bart.
The dining room window alternates between broken (from when the cat jumped through the window) and whole. This can be seen when Maggie is knocking over the dining room chairs (whole) and when Homer comes back with the pacifiers (broken).
In the beginning, Homer claims that he couldn't find Maggie's pacifier brand, hence why she started chewing on SLH's toy. However, when she appears again after the commercial break, Maggie has her pacifier again (although it could be possible that Marge and/or Homer was able to find her brand).
When Homer, Moe, Skinner and Apu get Rainier Wolfcastle out of his crashed car, it is shown that he had crashed into a stoplight. However, it also shows us that the stoplight is inexplicably in the middle of the road.