Hi all. Am using GPO in Sonar 6 for Windows XP. I'm not sure if this is a problem with Sonar or GPO. Sometimes when I am programming gradual tempo changes something happens with some intruments. In one section I was getting some weird sustain in Violin 1 Section even though the notes should have already stopped. When I undid the tempo change it was fine. I checked for CC64 errors but that wasn't a factor. Later in a different part an entire note didn't sound in Solo Flute 1 Vibrato if there was a tempo change drawn through its entrance. If I backed the change up so that it was steady when the note entered, it sounded.
I use XP and Sonar 6 as well as GPO. This sounds like a Sonar problem to me. If you are talking about a MIDI track you may be low on RAM, but if you're talking about an AUDIO track you may have a latency issue with your soundcard. (Although latency affects both i think - I'm no expert) Check the latency setting in Sonar Options > Audio > Mixing Latency. I have experienced the same thing and it's usually a too low latency setting with me. A 20msec to 30msec or greater latency setting might help. Good luck.
This sounds like the old Kontakt Player 1 DXi bug. I have yet to see it with Kontakt Player 2 and Kontakt 2 DXi. If you are still using KP1, you should update to GPO KP2 if you want to use DXi. Otherwise use the VSTi plugin.