A PR peculiarity

Zeal and DMOZ

[xy123]

I was browsing around Zeal and noticed that virtually every category is PR5, except the Zeal home page which is PR7. E.g.:

PR7: Home
PR5: Home > United States
PR5: Home > United States
PR5: Home > United States > New >
PR5: Home > United States > New > Computing
PR5: Home > United States > New > Computing > Software
PR5: Home > United States > New > Computing > Software > Operating Systems
PR5: Home > United States > New > Computing > Software > Operating Systems > Real-Time

which I find odd, because every page is in the google cache, and there are very few backlinks to them. E.g the last cat above has no back links.

Compare this to the equivalent category in DMOZ:

PR9: Home
PR8: Home > Computers
PR8: Home > Computers > Software
PR7: Home > Computers > Software > Operating Systems
PR6: Home > Computers > Software > Operating Systems > Realtime

which is more what I'd expect. Whilst I can understand why Zeal's homepage has lower PR than DMOZ, I do not understand why all cats except the homepage in Zeal are fixed at 5. I'd expect the deepest ones to have lower PR. I dont think the toolbar is showing estimated PR because the pages exist in google cache, yet at the deepest level have few backlinks as you'd expect.

Whats going on?

[I have no SEO interest in any of these computing cats]

[martinibuster]

I'm not and expert on server-side Web page generation, but they're using it (jhtml). I have a feeling that that has something to do with it.