mots:
Sounds like you solved your problem. Good.
Just remember there are several things to set up to get it all working: Importing the VSL "house style" (which contains the dictionary for translating Sibelius notation commands to VIPro-speak, plus special INSTRUMENT STAVES that must be used for the commands to work which you must use when setting up the score, not any will do), the proper Preset under "Sibelius" to the right in the VI Pro player (which you have discovered), setting up the proper CHANNELS in the mixer of VEPro, using AUTO in the mixer in the Sibelius program itself to sync-up the channels that are assigned to each staff in Sibelius (and thence to the mixer channels in VEPro), chosing the proper INSTRUMENT in VEPro for each channel using the Manual setup of the Sibelius play options. I think that's everything. Once you get something that works, be sure to separately SAVE it in the play options (separate from saving the score itself under File-Save). Any change to you play arrangement must be separately saved each time.
Another feature of VI Pro I only recently discovered: one of the faders in VI Pro is "Dyanmic Range Scaler"; this can be very powerful in separating whisper soft pianissimo from mezzo-forte, for example. You can place commands for each staff on the score, with the format "~CXX,YY" (note, "C", not "CC", where XX in the CC number, 30 in the case of Dynamic scaler, and YY is the value of the controller), such that in passages where greater dynamic range is required, you can increase the CC30 value. You will be surprised how the dynamic notation springs to life once you increase the CC30 value. For quite a while I had mine set at 63, and wondered why my work lacked much dynamic range, notation to the contrary. Similarly, for C7, which, along with C30, you can use like a conductor to change the relative loudness of players during playing. One other point worth mentioning: the mixer in Sibelius sets the default volume level to 100, not 127. I set it to 127, along with the final output in the VEPro mixer, using VEPro limiters and individual volume levels for channels to set my mix. It you don't notice the Sibelius mixer levels, you outputs will sound too quiet.
As I guess you've already found out, the VSL instruments along with Sibelius are quite amazing; I am especially liking the Dimension Strings, which allow you, on one staff, to have solo, divisi and all instruments together playing, creating great dynamic possibilities. Rather surprisingly some important articulations found in Dimension Strings are Not found in Solo Strings, Sul G, as an example.
You also have a great resource in this forum, which is pretty free flowing in commentary, and a very responsive VSL technical support for special problems. Check the forums first, since chances are your issue has already been addressed.
Steve