Yes, SQL Server is logging the changes that your making and NO, you cannot bypass the logging.

Use the SQL Server Profiler to determine the number of trips VFP is making to the server. I seem to remember a property that would control the number of commands sent back to the server in a trip (BatchSize maybe??) Also, for every update that you make, the indexes must be adjusted. Try to avoid updating the PK, especially since you mentioned that it's clustered.

-Mike