It seems as though my iPod sometimes gets a little confused about how to group videos together. In some cases, as in Dr. Horrible in the picture below, it groups them together, but in others, like with the two CSI episodes, it leaves them ungrouped. I've looked at the Get Info pages for both, and Dr. Horrible doesn't seem to have any more sorting information than CSI. Has anyone else run into this? What am I missing?