When I run a command "exec package_body.package_name" in the editor, the window becomes gray and locks up SQL Navigator until it is complete. I am not able to do anything else in SQL Navigator until the command is done running. If the package takes over a minute or so, I will see a (NOT RESPONDING) message at the top. If I am running a straight query, sometimes things will lock up the same way and sometimes it does not.
Waiting for fix to be released in a future version of SQL Navigator.