I know this is an old thread and nobody ever responded but I felt it made some valid points that could be useful for others who find it. Typically (not always) most sites have their homepage with the greatest number of backlinks and Pagerank, which means in Google's eyes the homepage is probably the most important page of your website. That means that any content on that page would have a better chance of ranking higher than any of your internal pages on your website.
Now this is not always the case because Google uses over 200 different signals to rank pages in their index, and sometimes you might get more valuable backlinks to internal pages. Pagerank, which is basically assessing the value of your backlinks to the pages is just one of those signals. So with that said it could be that your internal pages just do not get enough pagerank to rank for anything. There could be numerous reasons for this, maybe you have an issue with how you are linking to your internal pages, maybe your robots.txt file is configured incorrectly, or maybe your homepage which links to your internal pages just do not have much pagerank juice to pass down to them (assuming nothing else is linking you internally).
Also I noticed that your URLs have alot of variables in them, which is basically everything after the query delimiter, the '?'. Google can handle a few of them, but its smart to keep those limited as having too many on your URLs could potentially discourage Google from indexing them. Also if any of the pages get session ids also included in those queries and you aren't properly handling your sessions for Google (and other search engines), that could also cause indexing problems. I would recommend using mod_rewrite and having your pages rewritten on the fly to make them more SEO friendly. So instead of having something like:
default.aspx?Tab=2&Page=6&Article=682
you could have something like:
widget-page-title-page-6.html
Hopefully by now you have worked things out, but feel free to give us an update on if you ever resolved this.
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