I am having the same problem: when I play back from Sibelius and watch the perormance tab in VE I see that both the expression bar and the velocity bar are moving for each note. I have no idea where VSL is getting instructions to make controller changes. I am certainly not inputting Controller 11 changes, so Sibelius must be interpreting my input in the background and outputting it to VSL in this odd way.
I can't work effectively with the current implementation of VSL for Sibelius. I have tried: a) turning off the expression bar and using only velocity bar but then the dynamic range is far too small, b) going the other way around (turning off velocity) and using only the expression bar but this results in too artificial sounding playback (and ignores the whole point of owning VSL), c) I am now experimenting with changing the way Sibelius interprets dynamic markings by altering the dictionary. I plan to comendeer an unused controller such as controller 3, assign it to the expression bar, and thenhaving the expression text in Sibelius (e.g. ppp, pp , p , mp, mf, f, ff, fff) interpreted in the dictionary as controller 3 changes.
I am left puzzled as to the current implementation of VSL in Sibelius and don't see how anyone could create professional sounding recordings in its current state. So far, to ge the best out of VSL I must use Logic, and then it becomes quick and easy to blend sounds and make and edit controller changes.
I like the idea of Sibelius/VSL integration but so far I am quite disapointed and frustrated.
Plese lt me know if anyone come up with a solution to this problem with dynamics. Michael