Good Night,
Sadly (for me) the Scroll bar on Ubuntu 12.04 are still the same as Ubuntu 11.10. I particularly don't like it. So I tried the same method to disable the overlay scroll bar on Ubuntu 11.10 and Ubuntu 11.04, and it works! (I just tested the disable method.)
Use this:
# echo export LIBOVERLAY_SCROLLBAR=0 > /etc/X11/Xsession.d/80overlayscrollbars
If you try the other methods, please let us know if it works!
Remove or Disable Overlay Scrollbar – Ubuntu 11.10
Best Regards,,
Matheus
Ubuntu Tweak has an option to disable overlay scrollbars under Tweaks -> Miscellaneous
Installing Ubuntu Tweak:
http://www.noobslab.com/2011/12/install-ubuntu-tweak-06-on-ubuntu-1204.html
Works.