Which VST settings are you talking about? The whole AD setup, e.g. instrument selections, panning/mixing/EQ? Or SONAR-controlled parameters such as channel assignments, volume envelopes and routing?
The only thing I'm focusing on at the moment is the instrument selection. It keeps reverting back to the default, Instrument 1.
After it reverts to Instrument 1, it will actually still show the instrument I've selected in the 'Presets:' field in the upper left corner of the plugin UI, even though the lower portion of the plugin UI where all the knobs and sliders and hoohas are will have reverted back to the settings for Instrument 1. There's gotta be a solution to this!
For instance, in the SoHaSonata VSTi, I'll select preset 56:cygnus and cygnus will play as the voice on that track for a short while, then it will revert to preset 1:crystal pad, even though "56:cygnus" will still be displayed in the 'Presets:' field in the upper left of the plugin window. And even though it will still say "56:cygnus" in the 'Presets:' field, all the settings in the plugin UI will be changed back to the settings for preset 1:crystal pad.
In the Pro-53 VSTi. I'll select the preset "Analog Fretless" and Analog Fretless will play as the voice for a short while, then it will revert back to "Thin'n Cold" with all the Thin'n Cold settings, even though it still says "Analog Fretless" up in the 'Presets:' field.