Does changing from a hard business to a service based business affect rankings for those terms ?

[tremblay]

I am working on local search seo and for a while had my business ranking high in the maps listing. The problem was that we were listed as a hard business instead of a service area which is more what we do. (we are an event company.) After changing it i noticed that we dropped on alot of those terms. Does changing from a brick and mortar store to a service based business affect rankings for those terms. Do i have to rebuild relevancy? Is it just a waiting game.