CSI - Disappearing/Reappearing Pit Curtain
at aprox. 19 minutes into the episode, they show a close-up shot of the 7-10 spare, which was left earlier in the episode, which the bowler needed to finish the match. In the shot the pit curtain is missing, (you can tell because you can see the pin-wheel moving), but aprox one minute later, when they show the bowler picking up the 7-10 split, you can see the pit curtain has been replaced, because you can clearly see the pin bouncing off it.
CSI episode "Lovers Lanes"