Open one latex file in TXC.
Project -> Create with active file as main file
=== The window titlebar does not change and still show TeXnicCentre
File -> Save Project
=== Nothing change
Exit then reload the project
=== Titlebar updated.
I think it is better to update the titlebar as soon as the project is created. Especially for the Windows Taskbar that with an updated title is immediately much more useful (especially with more than one TXC open.