Strange happenings with sonar 8.5 64 and TTS-1

When I try to turn on the eq section of an instrument in TTS-1 while editing the instrument, the audio turns off. When I push the on off eq button again it comes back. Doesn't crash the engine just no sound. Anybody else had this one? Also if I put a tuner in as a track effect on any track it also mutes the sound. Any thoughts? Stock sonar 8.5 tweaked according to other users but not modified in any way. 32 bit version didn't do this. Seems to be a 64 bit with windows 7 thing.