Bubbles,
Contrary to some on this forum, I don't check the posts every day. But we are here now.
In the early building of the Half-Pint vendor, we were told by the manufacturer of the Sensit II system that the "eyes" that see the products drop were not sensitive to direct sunlight. That turned out to be incorrect; we tested and found out they are sensitive to direct sunlight. When the sun is low in the sky after sunrise or near sunset, the angle between the vendor and sun can allow direct sunlight to hit the sensors. We have only had problems in the northeast in the higher latitudes which may be the case here.
We have shipped some new parts for you to install, Bubbles, that should shield the sensors better than what we did when your vendor was built. This is the way we build them now.
Another thing that might be giving trouble are the florescent light bulbs in the vendor. Some of these bulbs create "electronic noise" (even though they look fine) that can interfere with the Sensit system. To check for this problem take both bulbs out and test the vendor for delivery. If it works, then add one bulb and test again. If it continues to work, then add the second bulb. If either bulb starts giving you the same problems as before then you know you have a bad bulb which needs to be replaced.
We try to avoid these "electronic glitches" by being very careful when we build them, but sometimes the "gremlins" get us. See if these fixes work for you and report back to us.
Uncle Sam