Jerky playback loop of .mp4 after being converted from .avi

Hi, I was wonder if anyone would be able to help with a small problem I'm having with an animation with a jerky playback once its converted from an .avi to an .mp4 (Sorry if this is a silly question, havent used mediaencoder before)

I have a 360 degree character turntable animation that was rendered as 199 frames at 24fps and saved out as jpegs.  I put the files into After effects as an image sequence and exported it as an 8 second .avi file at 24fps.   When I play the high res .avi, the turntable works fine and has a nice smooth motion which loops back to the first frame nicely for a continuous turn.  However the file was 700mb and I needed to convert it to an .mp4 to use on the web.  

When I put the .avi version into Mediaencoder and render out a .mp4 version everything looks fine and the turntable works well however on the last second I get a weird jerk in the playback before it loops into the first frame again (if that makes sence).  It didn't happen in the .avi file so I was wondering if I'm doing anything wrong in the render export settings of Mediaencoder and hope someone might be able to tell from my settings in the picture?