Matchmaker - S1-E7
Continuity mistake: In the opening scene at the bar, when Ted and Barney are discussing the idea of going to visit a Matchmaker, Ted's beer glass suddenly goes from being about a quarter full, to being nearly three-quarters full. (00:02:20)
Matchmaker - S1-E7
Continuity mistake: At the Matchmaker's office, when Barney is saying he just wants someone to hold, Ellen is seen putting her pencil down on the desk but in the next shot it is in her hand again. (00:03:50)
Matchmaker - S1-E7
Continuity mistake: When Marshall comes out of his room with the book about the Roswell Incident, he's holding the cover and first pages bent under the book, next shot he's just holding them normally, then they're bent again. (00:14:30)
Matchmaker - S1-E7
Continuity mistake: In the final scene at the Matchmaker's office, the tub of Haagen Daaz on the desk turns around between shots. Sometimes the brand name is visible, but in other shots the logo is facing away from the camera. (00:20:00)
Chosen answer: She was finally shown at the very end of the last episode of season 8, continuing into season 9. The actor's name is Cristin Milioti: http://www.imdb.com/name/nm2129662/.
Knever