Originally Posted by jtack
Just thought I'd follow up to say I did a bit of custom tweaking to the Modeline I'm using, and managed to get the Nvidia card I'm using to sync at 23.976Hz. Unfortunately I'm doing this remotely and won't be able to test in front of the Pio until tonight to see if the display is wonky or not.
Great news! My custom tweaked Modeline is working with the Pio at 23.976Hz.
My experimentation has revealed that there's actually quite a bit of wiggle room with respect to timing for a given mode. By fiddling with the pixel clock, I observed nearly a 1Hz permitted variance (approximately between 23.55Hz and 24.46Hz). I am not sure which of the Pioneer or the video card is the limiting factor with respect to these boundaries.
This range obviously easily covers both 23.976Hz and 24Hz. So I feel quite happy to say that the Kuro supports both these rates with its 3:3 mode, as others have speculated.
(Sheepishly, I must confess that although I previously announced that I couldn't make the Kuro sync at 24Hz "no matter what Modeline I threw at it," I actually had another Modeline later in the config file that was overriding the one I was playing with. Oops.)
This also explains how the BD player firmware update other posters mentioned actually fixed cadence problems. It's just a matter of adjusting the output signal timings based on whether the content is 23.976fps or 24fps.
I've also learned that Modelines are not necessarily equal between graphic chipsets. I came across a Modeline that was (so the poster claimed) specifically tweaked for Intel GMA G965, which, with my Nvidia 8600GT, resulted in a refresh rate of 23.95Hz.
For the benefit of Googlers who may come upon this post, here is the Modeline I've derived so far for Nvidia 8600 23.976Hz:
ModeLine "firstname.lastname@example.org" 74.059 1920 2558 2602 2718 1080 1084 1089 1137 +hsync +vsync