Version 7 of exec on windows oddity?

Example-1:

         tk_messageBox -message "before"
         exec -- [auto_execok cmd] << {
                 notepad
                 sleep 5
         } &
         tk_messageBox -message "after"

With example-1, everything works as expected:

1. the start message appears - it has to be confirmed
2. notepad starts (this by itself is an asynchron process)
3. sleep starts (because thats a console mode program, a separate console window appears)
4. the stop message appears immediately (because the whole cmd is started in background with &)
5. after 5 seconds sleep ends
6. notepad is still running

The main window of the tk prog stays responsive all the time.-

Example-2:

         tk_messageBox -message "before"
         exec -- [auto_execok cmd] << {
                 notepad
                 sleep 5
         }
         tk_messageBox -message "after"

With example-2, things are slightly different:

1. the start message appears - it has to be confirmed
2. notepad starts
3. sleep starts
4. the stop message appears immediately (because the whole cmd is started in background with &)
5. after 5 seconds sleep ends
6. notepad is still running

• The main window of the tk prog stays responsive all the time.-