Hi I have same problem, but it was when I changed to a new computer with W7x64.
I've tested back in my old computer and I have same problem (it was working before).
I've contacted with the support and it will cost around 60$ to fix my unit... I'm pretty sure that is a problem with YOUR software/hardware and I'm not agree with those taxes... I do not have any guarrantee because I purchased it two years ago, but I used it no more than 10 times.