Also, to add onto the very good points of @eatstoomuchjam, you likely have a display problem too.
Most modern computer devices (and potentially lots of smart TVs too??) run a 60Hz display. This will display 30p and 60p image streams perfectly with equal spacing between each new frame, but put a 24p video on there and you get jitter because the display isn't updating at a whole multiple of 24Hz.
Displays at 120p or 240p will not have this problem, or if you drive the display with a 24Hz input and have the display in the 24Hz mode.
This is the primary reason that I own a BM Ultrastudio Monitor 3G - it drives your reference monitor with the exact frame rate and resolution of the timeline, without any jitter.
I've compared 24p vs 30p vs 60p videos on a 60p display as well as through the Ultrastudio and there's a big difference - I prefer the 24p in both scenarios because it doesn't look so artificially smooth as 30p and 60p, but depending on what you value in an image and how you perceive motion, the jitter might tip the balance for you.
Unless you've got a dedicated output driving the monitor in the timeline frame rate, you really can't say anything at all about each frame rate because you're not seeing them properly.