Created attachment 109175 [details]
Dev build, JDK 7. Switched Nav mode to "Trees (NB Dev)" and started moving selection using the arrow keys. Suddenly the IDE froze with ~50% CPU.
Seems to happen frequently when selecting (not just expanding & viewing) nodes, so something to do with the corresponding selection in the open editor window.
org.netbeans.modules.java.debug.TreeNode is not production code. The tree element navigator is not shown to the regular users of the IDE --> P3.
And this whole module belongs to Lahvac ....