Backlinks and site pages don't match up

How does internal linking work?

[NexDog]

We have a forum archive that converts our php based forum pages into html pages. In the last dance, we got 16,200 pages listed when using site:domain.com domain.com

Each of these pages has a link to our main site but doing a link:domain.com only shows 436 backlinks. I thought that all our pages would count as a backlink - was I wrong or do I just need to wait? I know that 100 or so of those backlinks come from our site so what gives?

[Susanne]

The links count but Google will mostly not show links from pages with PR below 4.

[NexDog]

Don't think that's the case as I see lower PR links than that in our backlinks...

[mil2k]

Just to rephrase a bit:- only those page which google calculates as being important will be shown.

[NexDog]

Ah ok, gotcha..thanks.