With a normal installation, everything is ok.
Only the portable ff versions exhibit this behavior.
Make a clean installation and change two parameters.
a) Restore tabs from the last session
b) Don't load tabs until selected
Install the CopyAllUrls extension.
https://addons.mozilla.org/en-US/firefox/addon/copyallurls/
Change the option and add title before URL.
Now open some different sites and restart FF.
Click on Edit -> Copy All Urls -> Copy
and paste the result in an editor window.
Result with normal installation
Title Tab1
Url Tab1
Title Tab2
Url Tab2
Title Tab...
Url Tab...
with portable ff I get only
Url Tab1
Url Tab1
Url Tab2
Url Tab2
Url Tab...
Url Tab...
I don't know why but it is not possible to
access
gBrowser.browsers[i].webNavigation.document.title
it's always empty.
Only
gBrowser.tabs[i].label;
works.
I think I have more bugs in many extensions because of this.
I'm using Win7 x64 and I have checked the last 5 versions of FF.