Well, I am not sure how the pagerank got there, but there could be a number of ways.
1. It got there by using a redirect to another website. This is an example of fake PR.
2. It used to be a developed website, and now is at risk of losing its PR in the next google update, since there is no website there.
I also noticed in the whois that it is pending delete restorable.
http://www.iwhois.com/mainaccess.org
You might want to check that out.
for development purposes, mainaccess (nevermind the .org) sounds like some sort of ticket agency to me.
Anyways, best of luck with the domain and the website.
-Steve