Wrong brace behaviour when adding only one stave of piano

I hope it's not a duplicate. It's minor and easily corrected on the score.

Start a new score with (let say) a flute and a bassoon. Then add a piano, but only the bass stave.
(in 'instruments', add a piano at the end of the list and delete the 'treble stave').
--> result: the piano stave gets anyhow a brace that is here useless.

It event becomes funny if you move the piano(bass) between both other instruments:
- add a piano
- remove the treble stave
- move the piano(bass) between the flute and the bassoon.
- Click ok
--> result: there is a strange brace between the piano(bass) and the bassoon.

(win7 - version 2.0 RC)