Re: New format
You probably need to wait for the site to be indexed by the new version of the software - with 2M posts it might take a while (I'm guessing that the new version is taking advantage of the new MySQL search features which are being used by most prominent content management systems these days).
Or maybe they haven't switched the indexing on yet - the upgrade path from the old version to this one can be quite complex and time consuming, especially for a site of this size - you need to take things one step and a time 'cause it's all too easy to break it.
amofw