I have a project that won't playback in X2 without some of the MIDI dropping out. Dropout occurs on almost all midi tracks, but not all at the same time. In some cases a whole bar is silent. Other times only one note of a chord is sounded. The one softsynth that is not dropping out is Battery 3, but it's worse because instead some drum beats are playing late.
Altering the audio settings doesn't make the slightest difference. High CPU activity is not indicated. I'm wondering if maybe it's a particular plugin effect that's causing the problem. It's a big and complex project, which makes the problem hard to pin down.
The project was originally developed in Sonar 7, so I tried opening it in Sonar 7. It plays back perfectly there with no hint of any dropout. I now intend to work with it in S7 for a while and do some bouncing to audio before returning to X2.