This is strange: The homepage of Centrul Crestin Caleb has PR1. There are a few internal pages, such is the Prezentare, which has PR4. No extra SEO work was made for the internal pages and no authority sites are linking to them. So, in your opinion, why this radical difference?
May be the content in the internal page is unique and it drives much organic traffic through search engines.
PR4 page has a backlink from http://www.dezinspiration.com/ but anyway its strange because of internet page has more PR than homepage...I think your homepage will be pr4 on the next pagerank update
I agree with respect00, this thing happened with my site too some of pages were PR2 and the home page was PR1 but on the next PR update my home page got the PR3 and those pages still have PR2.