Have you restarted Windows Live Messenger since you made these initial changes?
If not the cause is likely related to how Messenger Plus! Live deals with interfaces. It loads them once then doesn't load them again.
To change this follow this posted by Patchou.
quote:
Originally posted by Patchou
Edit: for optimisation reasons, the information for every given window is loaded only once. As this would pretty annoying for someone who wants to try to change the files and see the results immediately, you can set a dword value "AlwaysReloadInterfaces=1" in "HKEY_CURRENT_USER\Software\Patchou\Messenger Plus! Live" to force Plus! to always reload the windows info.