Amir,
I do see the occurrences of a selected word being highlighted in MyEclipse Spring 10.6.
Can you please check if the related options are checked at Window > Preferences > Java > Editor > Mark Occurrences ? If all options are checked and you are still seeing issue, create a new project and see if the issue persists.
You can find the updated documentation at http://genuitec.com:8080/help/index.jsp
We have released MyEclipse for Spring 2013 SR2 recently and I suggest you please install MyEclipse Spring 2013 and take advantage of the enhancements and fixes we made since version 10.6.
Here is the link to download MyEclipse for Spring 2013 :
http://www.myeclipseide.com/index.php?name=Recommend_Us&req=Download&version=ME4S
You can install ME4S Spring 2013 to a different location along side your existing ME4S 10.x.
Let us know if you see any issues.