24Hz is the setting for many Blu-Ray discs, since film sources (movies) are actually filmed in 24Hz. Video sources (like TV shows) are filmed at 60Hz, and many trailers may be mastered in that category.
Many video enthusiasts like 24Hz because 24 frames per seconds gives more of a "movie feel", but not everyone is a fan. You may check the output menu of the game console to see if you can turn 24FPS or 24Hz features off. (I own the "other" game console", so I don't know what the menu looks like since the last update).
I do know in the standalone Blu-Ray players, you can toggle that feature. You might also adjust down the AutoMotion Plus 120Hz feature in the video menu to reduce some additional processing, which some say can cause a 'blurry' effect.
I just picked up a new ln52b630n1f, my blu ray player is my PS3, and from what i understand no current equipment plays at 120hz, and i understand that my tv will upscale the signal it is receiving to 120hz. but when i play my games on my ps3 the tv displat tells me that its running at 60hz, which is good enough for me. but when i put in a blu ray disc when the menu comes up for the movie it says its running at 60hz, but as soon as i begin to start the actually movie my screen flashes and then the tv display says its running at only 24hz? two days ago it said it was running at 60hz, but now that its only running at 24hz i can see a noticible difference with blurriness. How do i get my blu ray movies back to 60hz?