Ok I just found this answer from Mr Samsung on best buy's website that confirms what I posted about 24hz stutter and why your tv is not defective -
"All of the Samsung 1080p TVs will accept and display a 24Hz signal. However, on the panels that constantly upconvert the image to 120Hz/240Hz, as long as you have the Auto Motion Plus feature off for that source, you should be getting the true 24Hz signal on the screen. Although these panels will always be displaying the signal at 120Hz/240Hz, as long as the Auto Motion Plus feature is turned off, the panel will not be interpolating additional scenes (adding an additional interpolated frame between two original frames), and the 24Hz signal will look like its 24Hz and will not look "Hyper Real"."
So turn off AMP when outputting 24hz from your blu ray player and it will play the way it is intended. If you want AMP feature on, don't use 24hz as this will cause stutter. The two aren't supposed to be used together.