One of the things I noticed about you index page is that your pulling 9 different forums into the center "news/article" display. Each forum will use 2 queries. So in the center news/article you have 18 queries being used.
I have cut this in half with 5.0
Once I let 5.0 out the door your center section will use only 9 queries for those 9 forums.
For the time being if you limit the center to 2 or 3 boards with a 2 or 3 articles each your page generation times should decrease.
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