It's a constant source of irritation that hidden tracks keep re-appearing in my projects. I must be doing something wrong. On a regular basis I will do something which will cause maybe 50 previously hidden tracks to reappear in Track View, and I have to stop what I'm doing to re-hide them. Sometimes this happens if I open the Track Manager for the purposes of maybe unhiding one track, or whatever, but since it's been happening I'm very careful what I click on in that dialog, so I'm pretty sure I'm not accidentally unhiding things there, and it seems that it happens other times too, though I'm not sure about when exactly. Any ideas why this keeps happening?

You may have accidentally hit a shortcut to show all tracks. It is under "Z" key on my setup but cant remember if its generic shortcut or my own.

Locked Screenset?

Do you have it set in the track manager to keep the TV and CV in sync? i.e. track hidden in the TV are also hidden in the CV.