Well today when I checked ranks for all 5 keywords I saw my site sent to 5, 8 and 12th page for 5 keywords! I am quite sure google threw my site for forum backlinks! Even though the backlinks were from relevant forums and posts but as google recently devalued forum backlinks for SEO I think I got the kick for depending only on forum backlinks. Stupid spammers are really making SEO hard for us. They blasted backlinks using Xrumer and other automatic software and so google is even against of relevant forum posts.
See how many old backlinking methods are nowadays not working just for spamming...
-Forum backlinks (both profile and posts)
-Some web 2.0 websites are not working as they were once...
Spammers should have been hanged for spamming.