looking like google it got 2 sandboxex! like you escape from one, and get in the middle of serps....like 300-700 for some keywords ,and then you are escaped and get on #1-100 ?! I just realized this! I am on many keywords #1 on yahoo/msn but not also in google also yahoo got a kind of sandbox, that's allowing you to get for some very competitve keyworsds only in the middle of results?!
I've had a similar experience - the first breakthrough is to get a listing in the 100s, then the second is to get to where you belong