Finally have my computer working and have installed the Steinway and GPO4. I opened a double brass quartet I've been working on in Sonar and swapped GPO4 for GPO3. Loading the instruments was simple enough, and assigning outputs and channels was a breeze. Chaning the panning, though, has not worked so far.
I grab the pan knob and pull or push it to change the panning, but as soon as I release the mouse, the knob jumps back to its original setting.
What's the trick? And, where is the manual loaded - I haven't found it yet.