In addition to what Hilary suggests below, could you post the exact version
of SQL Server as well as the OS platform via:
Additionally, how many rows are in you FT-enable table ()? Depending upon
your answers to these questions, you might be able to take advantage of
CONTAINSTABLE and use its "Top_N_Rank" parameter, see KB article 240833
(Q240833) "FIX: Full-Text Search Performance Improved via Support for TOP"