Kenneth2 - 9:51 pm on May 23, 2011 (gmt 0)
I have seen sites with similar niche as mine ranked favorably with a large 300x250 ad (very high CTR) above fold.
Other things that I'm looking into.
1) Cross linking between my sites with Nofollow alt. (removed after reading an article about SERP demotion even with nofollow alt)
2) # of links per main page > 100 ( Site redesign on planning stage )
Another sleepless night ...