Something odd: at http://www.petri.co.il/disable_native_z ... ows_xp.htm, several ads still show even though they should've been blocked, like the LanGuard ads, that should match the "?adv=" filter with the "Check Parent Link" option checked.
However, when I add a filter for some of the other ads on that page, like the filter "=click" for the topmost banner, both filters start working and the ads that weren't blocked by the "?adv=" filter are now blocked by that filter.
What could be going on?