PR 0 in toolbar, not in datacentres

could be a penalty?

[lordbello]

Hi, I've been reading the recent google PR update on another thread in this site, where I've also learned how to check PR in different datacenters.
I've effectively noticed a PR change in the toolbar for my homepage, that dropped from 5 to 4. If this could be due to some changes in the back links, what appears more strange to me is that when I query datacenters, they return different values for PR, and that some internal pages in my site (linked from the homepage, though dynamic pages with variables in the querystring) still show PR 0 in the toolbar, while the datacenters say that their PR is between 2 and 3. The same happens for other dynamic pages in my site.
Can anybody help me figure out what is going on? Am I being penalized by G, maybe due to duplicated content? I have some cues:

- pages showing PR 0 on the toolbar (but that the datacenter says have PR > 0) are all dynamic pages (.asp).
- they are linked by the homepage by standard href links (no javascript).
- some of the pages are quite similar, because the content that is changing is just the list of products (which may have also very similar names), but
- i've placed some if - then code that could contrast this for some values of the querystring, so that at least 10 among about 80 of these pages are now quite different in content (I would like to post a percentage but the similar page checker is not working now)
- is thus the similarity between some pages that cause other pages (same file name but different querystring) to be penalized as well?
- can this result in toolbar showing PR0 in spite of different values in the datacentres?

Hope I've been clear. Thanks to anyone can help!

Stefano