Official comment
@Andrew > Please be aware that effective January 14th, Microsoft will discontinue support for Windows 7, and many vendors, Pioneer DJ included, will be following by no longer providing support or assistance for users who don't upgrade. Given that you're running Windows 7, and an i5 with 4GB of RAM, I would also suspect that your computer may be running low on resources, or require that you increase the audio buffer size to avoid underruns and distortion. You may also be experiencing an issue with the Intel Turbo Boost (which you can either disable in your BIOS or by throttling the CPU maximum to 99% in your Windows power settings).
@Doctor DJ > Same goes for you re: the buffer & turbo boost; please try those fixes first.