Try to manually add a (non-discovered) postgres server or jboss as or standalone jmx server into inventory. There is no place in the UI where the user can trigger a "manual add" for those kinds of servers. This used to be a righ-click option on the platform in the tree, but that is gone.
Created attachment 531594 [details] screenshot showing that i do see the Postgres Server type listed
Created attachment 531595 [details] Screenshot listing only limited items
Created attachment 531596 [details] Screenshot listing only limited items
I wasn't able to reproduce this. I see all the importable types, including the top-level server types, listed in both locations. [master 7f74d06] (http://git.fedorahosted.org/git/?p=rhq/rhq.git;a=commit;h=7f74d06) makes various improvements in the code used by coregui to load top-level server and service types (the types that are missing from Heiko's Import type selection menus). Heiko, I'm hoping I'll get lucky and this will fix things for you. Please give it another try and let me know.
Created attachment 531793 [details] That change helps a lot
changing status of VERIFIED BZs for JON 2.4.2 and JON 3.0 to CLOSED/CURRENTRELEASE