Dynamics while rendering a movie

I was trying to render a quicktime of a movie that used some cable actors with physics on it. Imagine a cable that has two points fixed, when it animates it looks kinda like a rubber band. In the viewport it looks awesome but when I render the movie, it freaks out and the physics goes wacky. I added 30 seconds of pre-roll just to try and fake it out, but it still freaks out. I"m using the new sequencer in 4.11.1