I think with the partial add-blocking list I got from the URL Tony posted, it takes a few minutes to process.

I've trimmed down my hosts file to pretty much nothing to do some testing. I've made a shortcut and it pops up a window for only a split second. Excellent.

After I reboot I'll put back the large hosts file and check out the impact. The moving/recreation of the hosts file is what may be causing it to re-initialize the entire list. That may be a limitation of the way the whole thing works though. I'll test it by adding one line with a text editor and see if the whole thing slows down again.

Bruno