I used to be a great supporter of PH but became disenchanted when each new release of Safari would break it and provide a myriad of issues to boot. I ditched PH in favour of the free Safari Adblock (http://www.versiontracker.com/dyn/moreinfo/macosx/33567) and have had trouble and ad free browsing ever since. Each Safari update is installed without the wait for the developer to update (the one month wait for the Safari 3 update was the deal breaker), no wasting time going in to packages and hacking to get things running again.