Ubuntu 11.04 is here, along with some interesting changes.
One of these changes is overlay scrollbars.
This means your scrollbar will not be visible until you move your mouse over to the side where the scrollbar would normally be.
If you’re really annoyed with this “enhancement”, here’s how to put it back into the “old fashion” way of doing things (with a scroll-bar always present).
Open a terminal and drop this line:
sudo suThen, restart.
echo”export LIBOVERLAY_SCROLLBAR=0″ > /etc/X11/Xsession.d/80overlayscrollbars