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Tommy, If you completely dropped to nowhere for a phrase you ranked well for it may be more than just a little bit of pagerank lost through the redirect. What Holger says is true, but the amount lost is pretty insignificant. If you share the exact URLs (before and after) we may be able to look into it for you. The way your domain is set up with multiple nested subdomains could be causing an issue too. The more specific you can be (keywords, etc...) the easier it will be for people to give you relevant advise.