strange error made the device unusable

The unit comes with 2 USB connectors, so it can get enough energy from the computer to burn. So far so good. What is not so good, unfortunately, the burning itself was not working with my device. I tried several different blanks, always the same problems. The device burns example of a music CD only 2 songs, then it indicates that the CD is too small. Some times could not be regulating by restarting the computer or burning tools, most of the time but. This is extremely unsatisfactory and cost me a lot of mis-described blanks. So device back ..
The second point gets it, because at least the reading and the speed were a plus.