Groove~/Buffer issue

I am having this strange problem. I am using a complicated patch with 4 different groove's and associated buffers. After the Audio is on with the driver automatically selected (CoreAudio).... the first buffer starts playing no problem. Then each one after doesn't play. But if I unlock the patch and copy a LED to see if sound is coming out, it starts playing immediately (without having done anything with the LED). Likewise if I just open the DSP window in the option bar it will begin as well. I have been having to do this strange manual process for each consecutive groove/buffer after the first. Furthermore, sometimes (not too often) a groove will just stop playing (while others are still sounding), and I can't do anything to make it start again.

I am totally clueless. Any ideas??