UPDATE: This turned out to be a bug in R14 of the SDK tools. It has been fixed in R15 which was released on Oct/27/2013. Updating to the latest release solves
I stopped having problems disable the option: Automatically enable / disable scroll lock based on the scrollbar position.
Window> Preferences> Android> Logcat> uncheck the option above.
In my case, I'm using Eclipse + Android Developer Tools (Build: v22.6.2-1085508)
I suggest that if I want to use eclipse, download the full package from this link: http://developer.android.com/sdk/index.html
After downloading, download all available updates, less NDK.