A while back I had a problem with the Arduino environment reporting a dropped COM3 port on win7 pro 64 bit. After a few days of suffering, I finally solved this by turning off the PC, unplugging it, waiting a minute, then plugging it back in again.
Today, the same thing happened again (and I solved it the same way). It seems like it happened (with the PC running normally) just as I plugged the USB cable into the Arduino.
Is it unsafe to plug and unplug the Arduino USB cable while the PC is running?