"When I export my animation created with a DSLR the playback is choppy, or it does not playback at all, why?"
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One of the great things about using a DSLR is their amazingly high resolution. This is great for high quality, however most computers cannot play back large image files at 24-30 frames per second.
If you want to export to view the clips on your PC, change the resolution of the clips (height and width) to below 800 x 600 in size. Use Quicktime H.264 or WMV encoding. This should let you watch them OK on your system.
However, if you want to edit the clips, you should export them as uncompressed AVI or Quicktime or as an image sequence at full resolution - then open them in your video editor. Video editing software (like SMP) creates a low res file for playing back while editing, preserving the high quality file for when you export to DVD, etc.