I have a bit different experience with this. I don't have any kind of headtracker and get this pretty often with a bit of stutter to it. I have so far found out that is because of my USB-headphones.
This message about plugged trackir and unplugged trackir is showing up, with a bit of stutter at the same time, every time I put the USB-charger cable into my headphones or if I turn them on or off. Also this happens randomly when I have the headphones on no matter if the USB-charging cable is plugged or not.
I'm using Windows 10
Headphones are from Corsair and a USB-Wireless type.