I have twixtor, but it does this thing where it pauses momentarily in places it's not supposed to. like in this video I made for example:
(At the start)
I think it's because I have not enough ram.
It's probably because your FPS dropped at those moments when recording the replay. Make sure you get a solid 60 FPS throughout the recording. If it drops, re-record it. It's either that or your twixtor settings.