Eclipse doesn't highlight references anymore

Question

I have an odd problem. In Eclipse Ganymede, I used to be able to highlight a variable, and it would highlight the use of that variables in that method. However through some

Answer 1

There's a little "highlighter" icon on the toolbar - it toggles "Mark Occurrences".

You probably accidentally pressed it when trying to select a menu item at some point. I had a friend who did that with the "show selected element only" toolbar button...

You can either press it again or configure as Rytmis says.