Index.htm gets PR3 and rest of site gets 0, WHY?

Only root of site gets a pagerank

[Skinah]

I moved my site to a new host about 3 months ago and google is spidering the site fine. Its picking up new pages that I add however.

The toolbar shows that only the root page gets a pagerank 3 and all other pages get a PR of 0. This is weird as the exact same pages are mirrored at another location and they all have a pr of 2 excpet the root page which is 3 of course.
The site is located at www.pcmus.com and I even have a few PR6 pages linking to me now which google have indexed and besides the pr0 it should be much higher on the root.

Any help whould be great.

[Spica]

If you have the same pages somewhere else, you can get a duplicate content penalty.

[Skinah]

So how much different do the pages have to be to get around this? IE if i add " Australian Mirror" to every page and leave everything else identical will it still occur?

Also the index.htm pages are identical and yet its still getting a PR.

I'll remove the mirror site and see what happens as my servers a lot more stable now.

Thanks for the reply. If anyone knows how different the pages have to be that would be handy information to have.