Sorry, I dont have a PHP one that I know of, but I used a Perl based one, called adcycle(www.adcycle.com). It also can be run as a deamon assuming you have root, and that can serve 500,000 ads a day. I used it as that, but served only a few thousand. It is not free(30 day trial) then I think its 50. You might at least give it a shot unless you hate perl.
I've been using PhPAdsNew for a few months. Generally speaking I think it's excellent, though some of the older releases had a few bugs the latest development release seems fairly solid.
The only thing against it might be that it is TOO powerful. The wealth of features might be seen as overkill if you only want to rotate a few affiliate banners, but if you are selling advertising from third-parties it's fairly unbeatable and the price is right