STOP button does not work as documented in the 6.007 TBEditor

The TBEditor posts 'Run Completed' usually before the Output Window is fully open. I created a Lissajous graphics program with a delay pause at the top, middle, and bottom; allows me to resize the overly large output graphics area as well test the STOP button.

The TBEditor posts the 'Run Completed' before the graph is even started. As the Lissajous pattern is being plotted the STOP button does not bring up the STOP dialogue box, and the graph program does not halt. Also, any infinite loops I have created cannot be halted with anything-- not STOP, not ESC, not Ctrl-BREAK... nothing.