mine can accept 1080p only at 24hz, but not 1080/30 or 1080/60.
you lost me here...
hz in this context is frames per second. so 1080/24 would be 1920x1080 progressive format in 24 frames per second. i don't know which players can handle it, but some hd-dvd and i think all blu-ray can output at 1080/24, but some can only do 30hz or 60hz, i guess. 24fps is the film industry standard. my display is a 72hz display, so 24 works, i guess, because it's a factor of 72. i don't understand all the intricacies of it all, to be honest.
i guess the 24fps film standard comes into play with 3:2 pulldown modes that some tv's have. film based material has flags on the proper frames and the 3:2 pulldown smooths out judder. my set actually has something called 3:3 pulldown which works with the 72hz refresh rate and the 24fps film based material to create a smoother picture somehow.