Switches from G-clef to F-clef on the Score

[VictorT]

I recently bought a new PSR-S970. I find it is a fantastic instrument. Although I have a limited musical background, I enjoy many of its features. I found the owner's and reference manuals a bit arid but thanks to this forum, I could find an answer to many of the issues I met.

One application I like with my PSR-S970 is to listen to a midi file and play at the same time the melody with my right hand and another accompanying instrument with my left hand while following the score on the screen. Then when I am confident with my performance, I gradually dim (or close) the two corresponding channels.

Sometimes the score on the screen for the melody, switches from G-clef to F-clef back and forth; curiously when I open my file on my PC (with Notation Musician) the score is all in G-clef. How can I control the clef of the score on my S970. Unsuccessfully, I have tried the set up. Any suggestion?

Victor T.