Thanks, all! I called Member Accounting, and an interesting series of events lead us to here (one of which may be of interest to people buying DVC points):
1) The difference between the $676.25 and the $717.98 is because we had partial dues from December of last year (when we bought) that rolled over into this year. Now, the part of interest is that, when we were purchasing, we were told that DVC would cover the dues for December. Turns out, when they say that, they mean that they will roll them over and we won't have to pay them
in December, but we still have to pay them. Apparently others have mentioned this situation before and they're trying to have the salespeople stop saying that they'll cover the dues (or I guess be more clear about what that means).
2) DVC switched billing systems in February, and our bill for January never posted, so instead the system charged us $102.74 in February (a bit randomly, since that's not 2x our monthly dues). The $61.55 is the adjusted remainder for the rest of the year.
So, that's what happened with ours, and maybe some information of interest for others. The good news is, unless dues per point go up >10% next year, our monthly payments should be cheaper in 2015.
Thanks again!