Reverse Sandbox? Ranking well for top keywords, poorly for others

[Cirilo007]

Hi,
We are experiencing some weird results on google for one of our Real Estate website. We are ranking on the first or second position for popular keywords, but not in the first 2 pages for other unpopular keywords. People talking about the Sandbox explain the exact opposite. We wonder if our website has not been hit by a kind of filter.

For your information, we completly revamped the website in January, setting up 301 redirect from the old pages to the new ones. No changes for popular keywords in the SERPS (we did even better) but no internal pages are ranking for the other keywords.

Does the new pages would be hit by a filter? Anybody has experienced the same situation?

Please let us know
Thanks in advance for your feedback