No output display in the DBMS Output Window after running another statement (4265443)

After first running a query, then running a script, and finally, altering the initial query and running again; will stop sending output to the DBMS Output window.  

Below are the steps that illustrate the problem.  

1) Open a db connection. In the SQL editor window type this in:
begin
dbms_output.put_line('Hello world');
end;

2) Select View --> DBMS Output
to open the DBMS Output window.

3) Return to the SQL editor window, highlight the begin/end code snippet and click "execute statement" button (green right triangle icon).
View output on DBMS Output window. I usually switch windows by clicking on the tool bar at the bottom.

4) Open another sql window using the "create new tab using the default style" button ("SQL" on a page) and type in:
create table sandy_test( no number);
alter table sandy_test add( yes number);

5) Execute the create table code by clicking the "execute as script" icon (yellow lightening bolt on a page icon).
See the output "Table created. Table altered." in the output window at the bottom of the screen.  

6) Return to the first editor window above. Change the text slightly, like 'Hello world again'.
Highlight the begin/end block and execute using the "execute statement" button.  

7) Return to the DBMS Output window, and you will NOT see the "Hello world again" line added to the window.

WORKAROUND:
One has to exit Toad and restart Toad in to receive any DBMS output again.

STATUS:
Waiting for fix in a future version of Toad for Oracle.