404 error from permalinks importing after new hosting

I’m trying to switch to a new host company.

I’m having issues with my permalinks. When I import my blog posts they only work when the permalinks is set to default (http://chachingqueen.com/?p=123) but my site has been using the month/name format (http://chachingqueen.com/2012/02/sample-post/). I don’t want to switch to the default permalinks for many reasons.

When the permalinks are set to month/day I get a 404 error on the home page of blog and none of the posts show up there.

What’s up? How can I fix it?