When using Casio factory rhythms, I can select "FILL-IN" one or two beats before I want the fill-in to start. I have now written my own fill-in and saved it as a "USER RHYTHM". But now, for example, when I am playing the "NORMAL" rhythm I must select my new "NORMAL FILL-IN" on the exact beat that I want it to begin. I don't get that lead-in time anymore. Is this just the way it works or have I done something in error?