When I us the free online sitemap generator for [external links are visible to admins only] or [external links are visible to admins only] I've noticed that sometimes it does not find all of my pages. I noticed this when adding a page to each of those sites and running the generator and then saving over top of the sitemap file on our server and seeing that the file I just generated was smaller than the file saved on the server. That shouldn't be the case because the one on the server should have one less page because I just added a page.
I then tried to re-run the generator and looked at the number of pages it says it found and it is different the the sitemap it just created a few minutes ago. One report for [external links are visible to admins only] showed 184 pages and then another report 2 minutes later showed 145 pages and another report just minutes later showed 182 pages. What would be causing this discrepency any why would the generator miss some pages when running the report.