My one gripe with AdShield, and the reason I disabled it, is that if you have a certain site, URL, etc. that is in your "bad list" and there are "good" links and/or popups coming from those sites, I haven't found a way to tell which filter/URL/server string has caused those to be blocked. Like, let's say I am taking one of the canned lists that people have, but one of those filters is filtering out something I don't want filtered. How can I tell which is the offending entry?

PopUp Killer had a nice "log" feature that showed you which filters have been triggered, which made it easy to go get rid of a bad one. I couldn't figure out how to fix this on AdShield.