Working with Tizen IDE, I noticed the overlay doesn’t actually display for the scrollbar in Ubuntu 13.10. This isn’t so bad for vertical scrolling because I use the touchpad to scroll. For horizontal scrolling, it is a huge pain. I’ve never liked the overlays, and they don’t really fit well with Cinnamon.
Here’s how to set the scrollbars back to normal:
$ gsettings set com.canonical.desktop.interface scrollbar-mode normal
If you discover the normal mode causes problems for you, you can reset it to the overlay:
$ gsettings set com.canonical.desktop.interface scrollbar-mode overlay-auto
Or, if you prefer a GUI, open dconf-editor and expand the node on the left to com→canonical→desktop→interface, then select the scrollbar style you like best.