I bought 4 $5 dccduino from ebay, two of them worked right out of the box, while other two refused to work with "not in sync resp=0x0" error. dccduino requires drivers from their chinese site, I ended up installing them on a WinXP VM. Anyway, was about to give up hope for other two clones, assumed hardware issue, as some has mentioned above. What worked for me is using one of the working dccduino as ISP (see Arduino as ISP tutorials), after burning bootloader and deploying blink sketch they started working. They would now work directly connecting via usb, no need for Arduino as ISP after first attempt.