When you drag the the tabbed lists left fromt the trackheader further then the end of the current end of the trackheader (where the tracks start) the GUI gets scrambled: ie it seems that the track header is dissapeard but you’ll notice some scrambled lines on the tracks. After trying some things to recover the original state I noticed you can drag somewhere on the scrambled lines the trackheader back to the right >> from there you can open again it again
To test, just drag the tabbed lists completely to the right and the tracklist is gone.
Eli