Update:
I just loaded the beta 64 bit version of jamstix3 and saved the export from the 32 bit version. Removed the 32 bit jamstix and loaded the 64 bit Jamstix35. Imported the saved song file into Jamstix and off and running.
It seems the studdering vst problem was either JS or bitbridge since JS was the only 32 bit plug in the project.
I only have NI B4ii that is 32 bit if memory serves. If it causes any grief I guess I will just bounce it to a track after recording the midi and unload it until it is needed again.
So hopefully things can settle in and go smoothly now.