A question for del.icio.us

I am still working on developing a tool for analyzing community tags in del.icio.us, but I have run into a problem that messes up the data pretty significantly. I would be interested to know if anyone has any ideas what is going on.

The problem is this: del.icio.us says that there are about 5160 items tagged with nptech in its database. I think this number is correct. But you can see for yourself that, if you put the pagination on 100, you will get to the last page (the first time the tag was used) when you hit the 41st page.

That's only 4100-ish. Are there 1000 of our entries missing?