HI: Mario
There are some expansion boards available that increase
the polyphony, but I don't know the model number of the
boards.
I'm sure some one here can answer that one.

Which voices are you using when you have the dropouts ?

Piano with full sustain takes up allot of polyphony.
Organ does to.

I have had it happen a few times but not very often, but
your probably a better player than I am.

Denny