When logged in as SYSTEM, in Schema Browse | Jobs it shows no jobs even though there are dbms_jobs for the selected schema.
Depending on how the option "Check for access to DBA views" is set, Toad will query either the all_objects, dba_objects, or user_objects tables. If the user logged in does not have access to view one of these dictionaries, then the objects may not be displayed in the Schema Browser.
Go to View | Options | Start up and enable "Check for access to DBA views".
To verify what Toad is running, use Database | SQL Spool or Database | Monitor | SQL Monitor.