Oh well, some inspection with the midi monitor reveals that there are a bunch of sustain controllers floating around with the midi data created by this style. Those song positions that create long sounding notes even if the note durations are rather short are accompanied by some non zero sustain controller values. Typically these values are indeed 127. That seems to account for long sounding notes with short midi durations.

Now, why do different synthies create different outputs?

In the second bar with the shot, the notes start out with a sustain controller value 127. At the end of the note durations the sustain controller value is turned to 5, not to zero.

Apparently different synthies react differently to sustain controller values, such a 0 correnponding to 'off' and any value different from 0 may correspond to 'on'. The VSC DXi seemingly takes a value 5 just as this value, thus effectively switching off sustain.

That is an interesting problem that popped up recently over at the German forum ...

Martin