aha! I found you. I am one of the people having problems with the notes cutting out when I change chords on my keyboard. I don't have problems with Century Keys. It's the only keyboard on Magix that I can use. The other Vita instruments do the same as the pianos but I can get around the problem easier than with the piano sound because you don't have to use the sustain as much.
I have ordered Samplitude Music Studio 2014 because it is 64 bit rather than 32 but have not received it yet. I am hoping that MAYBE i will not have this problem with the new program but I am not optimistic.
Thanks for your input