Yup, same here. Trills won't stop once they've been triggered. It seems to work correctly for a little while (like a very little while—literally the first couple of times playing back) on a new score, but then it starts sticking on trills after that. I've gone through all the details in the Optimization pdf, have downloaded and re-installed all soundset-related stuff, and pretty everything else I can think of. I'm not sure this is true, but it seems to be connected to time signature changes and/or the addition of fermatas and other time-related alterations to the score (that is, things that change the absolute temporal location of the articulation changes)... but I'm really not sure about that...
It's been doing this for quite a while, actually, and I've just ignored it thus far, but I really have to get this working now. I have a couple of big projects starting **now** and I really need to stop fighting with this...
I'm unbelievably frustarted by Sibelius+VSL at this stage. Though, honestly, I'm not at all sure that this is VSL's problem. It's just that I have zero faith that Avid will fix it. (Please, please, Daniel et al. at Steinberg, get us something that we can use soon!) Since version 7 I've developed a deep and passionate hatred for Sibelius, but I'm totally tied in at this point... ugh... (that is, until Steinberg comes out with their offering)
But if anybody out there has had this problem and actually found a relaible fix... well... you may just save my life!