Description of problem: The summary says it all.
Fixed by commit a83f72e (in bugfixes branch). The context menu hint appears only on resources and autogroups. Subcategories don't have a context menu and therefore no hint.
Verified on JON build #152 - Revision: 10620 There is context menu hint appears on resources and autogroups. There is no context menu hint and context menu for Subcategories.
Mass-closure of verified bugs against JON.