When Sarah runs out of the shop where she's having a manicure, she has flip flops on and toe separators on her feet. After she talks to Jake and turns around to go back to finish her manicure, the separators are gone.
When the character Sarah is looking at the pictures on the refrigerator and asks who the man in the magazine page is, the pictures are in a staggered line. When the camera cuts back to her for her line "Dad's giving up idea sounds intriguing.." the pictures are more widely spaced and the picture of the man and woman is below the others. When the character Mark places his photos of men who are separated from their wives, the photos are back in the staggered line again.
When Sarah's family are trying to set her up at the beginning of the movie, her sister Carol shows her a photo of a man with his wife. When Carol turns to stick it on the fridge, the man and wife photo is already there.
When Sarah first meets her date (played by Christopher Plummer) there is no yellow rose on his table during his close up but then magically appears when Sarah asks him about it.
When Sarah is surfing the internet, there are no cables connected to her iBook, so she should be using an airport wifi connection. But on the next scene, when we see a close up of the menu bar, the airport wifi icon shows the airport connection turned off.
When Sarah is swimming to Jake's boat, a life preserver is visible across her shoulders under her shirt. When she is pulled into the boat, the vest is, of course, gone.
When Bobby joins the group and they sing "Come On, Get Happy", Bobby starts playing the piano while they're singing, but the instrument he's playing on is actually an organ and not a piano.
When Sarah breaks Bobby's glasses on her front steps, one lens falls to the ground and you hear glass break. But the style of glasses Bobby is wearing is semi-rimless and cannot be made with glass, as the fishing line that holds the lens in place cannot support the weight of glass lenses. His lenses would have to be made of plastic or polycarbonate.
Jake commented that nobody would remake Doctor Zhivago (1965), yet it had already been remade as Doctor Zhivago (2002). It has been remade again as Doktor Zhivago (2006).
When Dolly is showing Sarah her multiple personalities on different matchmaking web sites, her computer screen shows an Apple Mac OS X desktop. Then she goes on and tells Sarah how her computer is working for her 24 hours a day "God bless its little Pentium-chip heart". Apple Mac OS X did not run on Intel Pentium computers when the movie was filmed.
While at the meat counter in the grocery store, the butcher announces that the special is whole fryers. "Two breasts, two thighs and a wing." Aside from the fact that a whole fryer has more parts, do they really mean only a wing? Are these mutant chickens? Although, it's quite possible, this line was meant as a joke.