The cursor position is not always updated, especially when using the right and left arrows on the keyboard. It is usually updated when pressing the up or down arrows on the keyboard.
Note I am using Linux Mint MATE version 17.
From the Start menu at the bottom left of the screen, choose Applications -> System -> Preferences -> Windows.
Then enable compositing under the General tab.
The inspiration for the experimentation that lead me to this fix was provided by a blog about a bug in window compositing in Linux Mint MATE 15.