José,
I am almost sure that the cause are all those aftertouch events; maybe Ketrons respond differently than Yamahas to aftertouch; in any case, there should be no aftertouch on a piano midifile.
As I wrote, I could get rid of those events one by one, but I don't know how important it can still be and I hope to get an answer to my question: how can I delete all the aftertouch events with one single action?

[This message has been edited by Dreamer (edited 11-27-2002).]
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Korg Kronos 61 and PA3X-Pro76, Roland G-70, BK7-m and Integra 7, Casio PX-5S, Fender Stratocaster with Fralin pickups, Fender Stratocaster with Kinman pickups, vintage Gibson SG standard.