In version 1.6.1, when a test is created that contains a package with an overloaded function, and when it's opened in the test builder, Code Tester lists more versions of the function than actually exists.
Manual edits can be made to get the test definition in sync with the changed header, through the Test Editor.
See Help doc "Update Test Definition After Program Changes".
Issue fixed in Quest Code Tester 1.8.0. The latest version of Quest Code Tester can be downloaded here.