Results undesirably randomized in fulltext search
I am running a simple query that performs a fulltext search and sorts by score. Everything has been running fine for months now when suddenly I am seeing random results returned in some cases, in others I see less results returned than should be, and in others I see results that are the same but randomly sorted.
I tried copying the database over to another server and ran the exact same fulltext query there. The results that come back are consistantly what is to be expected on this other server.
What could cause such differing results with the same database and query on two separate machines with the same setup?