Hi Ralf, this did the trick – screen stopped spinning like crazy. One thing I noticed: my values were nowhere near -1.0. They were: -1000000,000000 (note: modified regional settings here using comma and period inverted – Brazil).
Right now it’s not possible for me to keep plugging/unplugging USBs (case is inserted into the furniture, will move it to another place in a few weeks), so I’ll test again removing all USBs later. I mainly want to play a few platformers with some 3D, so headtracking isn’t a priority right now.
Thanks for the help!