OK. You said 'timekeeper rates' in your original post.

In the main program and Time and Disbursement batch entry, if the user has security access to Edit Batches then they can edit any field including the rates. There are no specific security settings to disable access to certain fields. I can forward this as a suggestion for a future release.

Perhaps for those users that you would prefer to lock down the rates, then using TimeKeeper or an Excel file for importing to keep track of time may be useful.