The keyword tracker reports 981 pages in URL whereas google reports 13,600. This has been the case for weeks now, does pages in URL just mean cached pages or is this something that will sort itself out over time?
It only updates when back links change. It's primarily a back link tracker, not a pages in URL (or PageRank) tracker.
Try entering in the same url with a forward slash i.e. www.bluewidgets.com/ (or without it if you are already doing that). It will give you the current figure being reported by the api.