Spell check in use error Office 2k

After upgrading to office 2k sp1 from office 97, 2 out of 30 users are experiencing a bizzare problem. They recieve “spell check in use” errors in word. The spell checker isn’t in use, and even if every other application is closed, they still get the error. It is only happening on 2 out of 30 machines that were upgraded. Any thoughts?