With Kepler, the buttons in the Console view are sometimes rendered like this:
Various rendering bugs are discussed in this bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=333965
The solution is starting Eclipse with
GDK_NATIVE_WINDOWS=1 ...path.to../eclipse.exe
or
export GDK_NATIVE_WINDOWS=1 ...path.to../eclipse.exe