I am having same issue with TrackIR after 1.7 update. When I start to build a structure or get into vehicles driver position my character head turns to 180 degrees. I have to hold Alt key and use mouse to return head back. This happens constantly when I try to build, and less when I get into driver seat. TrackIR worked fine before 1.7 update. Another problem is when character running sometimes. When I walk Trackir works fine, when I press Shift to run the character head jumps to look up, when I release Shift key character head returns back.