I have 5 mini sites (5 months old) which are doing nicely (position #1-3) on Bing and Yahoo. However, I can't get to page #1 on Google. Every time these web pages got to page #2-3, they stayed for couple days and then disappeared. They're still indexed though. One page did get to #5 for 2 weeks and then headed straight to last page. I thought that the way I did link building (manually blog comments and forum profiles) may cause a red flag, so for testing, I has stopped adding link to one of my last mini site for 3 weeks. That site climbs to position # 16 on Sunday, and as predicted, it is gone today (not on top 1000). I hope someone can give me a solution to get my sites back.