Posting this cause I wan’t aware and the only other post I found was dated January.
Since Paypal purchased Verisign they are discontinuing the pfpro extension to PHP. And in fact, what I’m reading is that Sept 2009 is the end of life for that functionality, meaning requests will not work beyond that point.
For sites using pfpro that ned to transition, the solution is
1) use the java sdk
2) use the .net sdk
3) write your own api to utilize curl and https
4) use a public api for curl and https a la This post from the paypal developer forum
this means if you’re installing a 64 bit system, you’re pretty much screwed because there are no new libraries/binaries released for pfpro under that platform… unless you’re running a .net or java solution.