i've installed the metrics plugin and restarted eclipse ganymede. i could open the view, but in the context-menu of my java-project there's no possibility to enable the metrics.
I just installed version 1.3.6 in JBoss Developer Studio, and I'm having the same issue. I can get open the Metrics View, but the context menu for the project (any project) and the project properties do not show any entry that begins with "Metrics".
Work-around: In Eclipse (JBoss Dev Studio), I went to Window > Preferences and found "Metrics Preferences". Clicked on "Restore Defaults" (even though I hadn't actually changed anything), "Apply", and "OK". Then went Project > Properties and found the Metrics entry.