As per title. These would be the arrows next to the track view track volume meters.
 
I open a file, they are gone:
https://dl.dropboxusercon...0arrows%20vanished.JPG
Yes, I have tried fully expanding the tracks to give the arroows plenty of room to appear. They just don't.  

I close the file and open its immediate predecessor, which differs only with respect to some FX parameters,  and they are where they should be. 
https://dl.dropboxusercon...they%20should%20be.JPG
Any ideas?
 
What next, Sonar? 

Probably not arbitrary, the toggle for the option is in the Track View View Menu called "Auto Track Zoom"
keyboard shortcut SHIFT+Z

exactly what Steve said. if you click on a track and it expands, then there's a good chance you are in Auto zoom mode.
In Auto zoom, every time you click on a track header, that header will expand and the others will minimize automatically. This feature does have its uses.
 
However... I use it about as much as I use the Matrix view.
which is never.

scook
Probably not arbitrary, the toggle for the option is in the Track View View Menu called "Auto Track Zoom"
keyboard shortcut SHIFT+Z

Ach, I'm all wet, you were right.  I must have accidentally hit shift +z instead of control + z at some point.
 
The keyboard sometimes becomes a real minefield with Sonar... just recently, despite selecting "Give all keystrokes to [selected] plugin", it didn't, though I didn't notice that at first; by the time I'd exited the plug I didn't recognize the project, it was like waking up in someone elses' house...