If you start gnome-terminal in gnome, and then log out saving settings, when you log in again the window title is blank (and shows up as '???' in the panel).
gnome-terminal code looks correct to me; this is likely a session manager or gnome-libs problem. Needs a fairly in-depth investigation.
any progress here?
It works for me in Rawhide if you set the title with the --title command line argument; if you set the title with terminal escape sequences it deliberately doesn't remember the title, since this is typically used to report current directory.