By choppy render you're either dropping frames because the data rate is too high for your hardware to handle or you're getting stroboscopic effects like the effect where a stagecoach wheel's move backwards at certain speeds. Stroboscopic effects happen when the frame rate and the movement of the pixels end up just out of sync. Our brain processes the moving image as something other than what it is. Dropping frames in playback was my first reply because it's probably what is going on. It's not possible for AE to render frames out of order or to skip frames in the composition using any of the default render settings.
I'm not seeing any system specs but it would take quite a hurky machine to playback HDTV Photo Jpeg movies without occasionally droping a frame or two. I'd drop your rendered footage into the Adobe Media Encoder and pick one of the delivery formats for the web like H264 and YouTube Widescreen HD and check the compressed movie in your media player. It's most likely gong to be just fine.
My machine is a 2008 Macbook Pro 2.8 dual-core with 4gig's of ram and alot of programs on it so I think you are probably right!. It's choppy in the sense that playback of the animation is not smooth. I have text before we see the animation with a decoder text preset on it and a wiggle expression which renders very smoothly and no problem. However after this I start off with a close up of the earth(radius is quite high) and I am rotating the globe slowly. As maybe ten to fifteen seconds pass I reduce the radius size as it still is rotating. Sometimes I get relatively smooth playback and other times I drop a large amount of frames in the animation, so it seems to be my system. I'll try encoding for the web as you suggested and i'll report back
Thanks Rick you were right my machine just was dropping frames due to the Photo jPEG format. I tried H.264 and I got much smoother results.