Staff name error when adding new instrument

On MuseScore 0.9.5, I have written a piano part.
Image 1 : The name of the staff : Piano (of course !).

Images 2 and 3 : When adding new instruments above the piano staff, the name of the new first staff is still "piano" instead of "Violins 1".

Image 4 : If I try to change it by editing the name, the name of the first staff AND the name of the piano staff are changed together.

Image 5 :If I do nothing but saving the file, closing it and re-opening it. Then everything is ok (right name on the right staff !!)

It's magic ;-)

See You