Keys sometimes do not sound

[Lant]

Hola,
I just acquired Rev2 8, in some patches there are keys that sound very quiet or do not sound and when you press them again they sound, I press again and they do not sound, then it sounds low ............
So are patches?
It also sometimes blocks, hangs up.

Thank

[Lant]

I was not in multimode, now it works fine.
But I worry about hanging up