As with any product, there may be a few bad units, but in your case, it may have been a bad production run. Just like rusirius, I have not had any issues with mine, and I love this thing.
Well, I have had ONE issue, and that was solved by myself. For me, I had the same issue of it powering off, but in my case, it was the screw to the right of the USB port (if you're looking at the bottom, and the USB port is toward the top of the battery plate). If this screw is not tightened all the way, the plate does not make contact and it will power off, or power off and on, off and on, etc. I wrote a post about it in another T5 thread. I think "Cloupor T5 battery" was the thread name, and the reply is on page 4.
Now in response to mgmrick, I too have had a similar thing happen with another VV/VW device. It was the Dovpo E-Mech. I loved that thing, but the first one I had went belly up. I plugged in the USB charger and the port broke off and rattled around inside. I had it replaced, and the second one had a display that was separating from the body, and then the USB port came lose and was about to break off as well. That's when I bought the T5 and placed the E-Mech on the shelf to just sit and look pretty. I have no doubt that these were random issues, but still, it can happen.