Sometimes much less URLs in my sitemap?

How can it happen that if I create a new sitemap I get as the summary for example -241 URLs? I've not deleted any member or any thread and I don't think that my moderators removed 241 posts at once. Those large minus numbers are sometimes in the ShowPost URLs, someadays I get then a plus of hundrets of showposts as the difference between two generates.

That's confusing me. Is that ok? Or could it be a bug?

Does it happen often? Could you please backup of sitemaps for some time to be able to compare them?

Ok, I'll create backups within the next days.

Sometimes there are more days where nothing happens, but then from one day to another there is sometimes a large minus.

i think its normal... to some extent. i get it too.

here's a chunk:

50 2006-08-02 04:00 89.94 s 99,763 +128 Yes View details | Remove record
51 2006-08-03 04:00 84.91 s 99,875 +112 Yes View details | Remove record
52 2006-08-03 16:05 88.50 s 101,000 +1,125 Yes View details | Remove record
53 2006-08-04 04:00 89.52 s 100,011 -989 Yes View details | Remove record
54 2006-08-05 04:00 87.39 s 100,143 +132 Yes View details | Remove record
55 2006-08-07 04:00 52.79 s 100,342 +199 Yes View details | Remove record
56 2006-08-08 02:00 53.86 s 100,483 +141 Yes View details | Remove record
57 2006-08-09 02:00 52.77 s 97,483 -3,000 Yes View details | Remove record
58 2006-08-10 02:00 57.42 s 97,608 +125 Yes View details | Remove record
59 2006-08-11 02:00 47.94 s 97,714 +106 Yes View details | Remove record