If a user connects to an 11g Database and starts debugging any simple procedure and then uses the Terminate execution button, Toad freezes or locks up. User is forced to terminate the Toad.exe task from the Task Manager.
Incompatibilities with the 11g Oracle Database.
WORKAROUND:
Create the procedure in a 10g Oracle Database Server and debug it there, if available.
STATUS:
Waiting for fix to be released in a future version of Toad for Oracle.