Only a bit confusing. Hopefully I have defragged it right and answered your questions [img]/infopop/emoticons/icon_wink.gif[/img]
First, I read in this forum that Google only shows the backward links for sites with a PR of 4 or higher (but G does indeed know the links are there for lower PR sites). This matches what I have usually seen with my own sites. They would show 0 links most of the time until I reached PR 4...
Second, the other pages on some sites show as backward links NOT because they are listed on a links/partners page! There is most likely a link off of the pages themselves--usually to the home page of the site in question. This is commonly part of the normal navigational structure of the site. Those are "internal links"--links which go to other pages of the same site.
Internal links do not count as much as external links (external being when some other site links to you)--but they do count to a point, most likely because they give an indication of the size of the site. A site which has 10,000 internal links is going to be a whole lot bigger than a site with 5.
A links/partners page usually has OUT-links and therefore does not generate backward links to the site it's on (except for the navigation links). It generates backward links for the link partners listed on it. If those partners reciprocate, that gives the backward links to the original site.
And some sites can to get people to link with them without having to give a recip. If they get "free" links this way, those will show up in the Backward Links without there being a recip on the links/partners page.
And if you have PR under 4, usually nothing will show up in the Backward Links but every few months a fluke happens. But Google does know about your links--if they didn't, or chose to ignore them, you'd have PR Zero or maybe 1. "1" is usually when Google only knows about a link or two--common with new sites that only HAVE a link or two coming in...