Problem with MIDI (change notes)

Hi. Since I installed Sonar Professional, I have seen that using Rapture Pro, it randomly reproduces correctly the notes, or runs I think a semitone. I can not understand if there is any logic. I do not click on a weird button, I just play it in a simple way. Sometimes it reproduces well, sometimes not.
I do not know if in the rest of VSTi happens, I do not remember, I think it is enough to happen in Rapture.
Could it be that he is doing something wrong? Any help will be welcome.
(I use Google translator, my language is Spanish, I comment on any problem in the writing).
Thank you very much.