Perhaps it's the Windows version you're runnning. Mine is running on XP. By default (that is without implementing any of the suggestion here), it won't even keep the column widths WITHIN THE SAME SONG.

If I change the widths for (say) Guitar, then close that window and open it again, they revert back to default width. Same if I open (say) Piano, after setting the widths for Guitar.

I assume we're all talking about 2015 (417), and getting to that window by right clicking on the radio button label and selecting "Add/Remove RealTracks".

LLOYD S