Mother's Little Helper - S7-E7
Continuity mistake: When Kitty is showing Red "The Joy Of Sex" in the kitchen, the book goes from open to shut instantly between shots.
Continuity mistake: When Donna introduces Sarah to the gang, she states that it took her 6 months of sorting records to become 'Hot Donna'. In season 3 episode 14 "Radio Daze" Donna has just started working there and gets the name 'Hot Donna' immediately. (00:01:20)
Oh, Baby We Got a Good Thing Goin' - S7-E18
Continuity mistake: When Kelso is trying to get the baby to not cry, you can tell Bob covers its face to the camera so we don't see that it's not actually crying. Cut to a different angle, and the blanket surrounding the baby has moved. Cut back, and the blanket is covering the baby again.
Continuity mistake: In the crowd scenes, Jackie comes back to her seat. A man sitting next to Donna looks at Jackie. The scene changes angles, and the man is looking straight.
Answer: It's Ashton Kutcher's dog.