You guys rock!!! I buy all my supplies from you. I have a question; I recently bought a pack of 510 blank cartos from you ( which I absolutely love by the way), and 3 of them didn't work when I filled them up, so I turned the middle part on the connector side just a little, then they worked great. But after I'd say about 20 hours, they stopped working. Is the middle part on the connection side supposed to be turned a certain way or even turned at all? Because the other 2 I used, I just filled them up, connected them to the battery and they worked flawlessly. In any case I just ordered 2 more packs of blank cartos and a mega battery. KEEP UP THE GREAT SERVICE!!!!