Goofs

When Serena pours the drink over Franklyn's head, his hair falls down over his eyes. In the next shot, his hair is no longer in front of his eyes.

Before the mid point: After Serena zaps up a full course of dinner on the table, Samantha zaps it off. According to the series' rule, only the one who casts a spell can undo it.

Correction: First of all, it was stated several times in the series that if the witch knows the spell, she can undo it. Second, Samantha wasn't undoing Serena's spell, she was casting a new one - removing the meal that Serena put there.

At 7:52 when John Fiedler (Mr. Beams) enters the room and informs Serena about her luncheon date, the actress playing Samantha's double turns her head, exposing her face and revealing that she's a double.

In the last scene, when Serena tries a second dating service, it is visible several times that there is a double sitting in for Serena. Her face is visible when they are sitting on the couch as the matchmaker runs the computer, when both women get up to walk out the door, and several times when they stick their head through the door to listen in on the conversation.

In a scene using a matte box to show Samantha and Serena together, exposure on the left side of the matte line is noticeably different from that on the right.

When Samantha is talking to Serena on the sofa, a shot of facing each other together shows a difference in lighting. Serena's side of the shot is much brighter than on Samantha's side which points to two films patched together.

In the opening (kitchen) scene, the wires holding up the "floating" knife and piece of cake are visible.