Thanks for your response. No actually its the opposite – the footage was shot and then processed in premiere at 24 fps – the Vimeo preset is 30 fps but is smooth but the HDTV 1080p 24 is not.
The file size on the Vimeo version is 250 MB and the HDTV is just under 1 GB and the latter has much higher bitrate settings. Could this be why its not playing back smooth? I would have thought my computer would have sufficient processing power to handle this though.
When looking at the picture the movement looks symptomatic of your description of duplicated frames but if the frame rate is consistent then that can’t be the problem right?