Locked tabs sometimes get modified

[WengH]

Usually, when I open a folder from a locked tab, a new tab with that path is opened.
Sometimes (like 1/50), however, the path of the locked tab is modified and I have to unlock, change path, rename, and lock again to solve the problem. It's very annoying and makes me forget what I was doing...
I can't find any cause of that problem, it seems to happen randomly. Must be very hard to debug

[admin]

Note that there are two ways to break the lock:

1) Hold Ctrl+Alt while you click on a new location -> the locked tab will change to that location.

2) If the locked tab is the default tab as well it will change location when you are coming from another locked tab.