Hey TC - do me a favor please. Look at pulley on the rear wheel. Look at it from the rear of the bike and position yourself directly behind it. Trijetdoc and I noticed that on our RUSEs the belt rides all the way outboard and touches the lip of the pulley. The lip has slightly 'polished' the edge of the belt. On the 07 jester it is more in the middle of the pulley. Don't know that this is a problem or an issue - just different and wondering if 'they are all that way', lol.
If the wheel is not exactly true, the belt will have a tendency to "walk" to one side of the pulley or the other. As you have described on the RUSEs, my guess is that the left side of the rear axle is slightly forward of the right side, having the rear wheel skewed more to the right. This may be so slight that it makes no noticeable feel when riding or even effect to the tire wear but it exist. Sounds like the 07 jester is running true.