I had the same problem.
You can download Kepler with preinstalled mylyn. Like "Eclipse IDE for Java Developers" package.
Question
OS: Gentoo Linux
Java VM: Oracle JRE 1.7.0.25 [oracle-jre-bin-1.7]
I installed Eclipse Kepler x86 at home and x64 at work from the official website. Also I've installed PDT and Mylyn. Here's what I noticed:
In x64 edition "Focus on Active Task" button is missing, but it's available in x86 edition:
I've even tried to copy .metadata catalogue from home workspace to work. As a result all settings have been added correctly, but this button is still missing...
Also the .metadata catalogue probably has some leftovers from Eclipse Indigo that I used before.
How can I add this button to x64 edition?
Thanks a lot in advance!
Solution
I had the same problem.
You can download Kepler with preinstalled mylyn. Like "Eclipse IDE for Java Developers" package.