Why does my iTunes hang every time when using automatic device detect?

Why does my iTunes hang every time that I connect either of my devices (iTouch-4th Gen, iPod Nano-5th Gen), to my Win 7 (64-bit) PC desktop? By the way, this does not happen if I open iTunes first, and then connect the device. So my workaround was to simply uncheck the checkbox that allows iTunes to start automatically upon device connection. This doesn't fix the problem, but it allows me to synch my device, but it would be nice to be able to have the autodetect work properly, so that iTunes would start normally without locking up on me and freezing. That's what I mean by 'hanging'. My whole computer doesn't freeze--only iTunes.