Looks like someone recalculated measure boundaries when the time sig went from 5/4 to 6/4.
30 measures @ 5/4 is 150 beats,
then 150 beats @ 6/4 is suddenly 25 measures.
The next measure @ 5/4 is 31, the next measure @ 6/4 is 26. Bug, but is it in both VSTs or is Sonar giving a different measure to the VSTs from what it uses for itself?
Do the VSTs need to be told by the user when there is to be a meter change or does the API provide for that I wonder?
Anything different happen when you start playback @ measure 31?