Changing note pitch by using up/down arrows has unexpected behaviour.

I'm sorry if this bug was reported twice. I look for something similar, but I didn't found. The attached file is going to be some scales and arpeggio exercises in C# Major.

Steps to reproduce the bug:

1. Move pitch of an e sharp up, like in 54 measure.
2. Pitch will change to a f sharp.
3. After that, no matter what you do, there is no way to get again an e sharp. Instead, you will get a natural f .
4. If you reach a natural e, and then you add a sharp from the note entry pallete, the program daws a sharp next to the e, wich is not necesary.

If you let the natural f, save the file and reload, it appears again as a e sharp.