Now I've discovered that the "Find usages" isn't working, either. (RM 6.3 on Ubuntu).
For some methods it works fine, but for other methods in the same Class (or Module) when I right-click and select "Find Usages" a little yellow balloon appears in the bottom left corner of the IDE (over the "Find" button), but it just stays there and nothing happens. Then it goes away when you click elsewhere in the IDE.
Any thoughts on this one?