Sgt_Kickaxe - 3:20 pm on Jul 12, 2011 (gmt 0)
Whatson you may be feeling the effects of what Panda is doing to other sites, specifically the sites in your backlink profile. A quick look at GWT and at some popular backlink checking tools shows a declining trend in number of backlinks for ALL websites.
Panda seems to have made Google stingier on what is considered a qualified backlink. As the sites in your backlink profile go down, so do you.