It's really hard to isolate the problem to a particular song. I have encountered this issue rather infrequently, but frequently enough to be quite distressing. It happens usually upon entering an entire song from the beginning.

Clue: Often I don't know in advance how many bars are going to be in the song, since the song is one I'm composing in real-time. I mark the end of the song several times, extending "white-space" about eight bars at a time as I need it. I'm not sure if this has something to do with the problem.

Trigger: The issue almost always happens, as I stated earlier, upon changing the part marker near the bottom of the song. This event triggers a reflow of the bars to insert a part division (gray line) and move the marked bar to the beginning of the next line. It is at this moment that BIAB is trying to reflow the bar lines while at the same time attempting to shrink the text size to fit the window. For some reason BIAB "thinks" that it can display the entire eighty bars (for instance) in the window, but can't; so everything becomes squashed to the point that bar lines are overwritten to the point that no text can be seen, not because it's too small but because it is overwritten.

The only thing for me to do at this point is page up, hit play, or initiate some action that will refresh the window. Regardless of what I do, the refresh straightens up the display correctly, but the chords remaining are from some point much earlier in my work session.

I have pulled all the known tricks out of the book that I have known since BIAB version 7, but to no avail.

Joel