After rebooting, I started VA again and this time I tried to edit the profile and that started the process I described earlier and I had to power down again.
Does the command run when VoiceAttack loads the profile? Opening the "Edit a Profile" window shouldn't trigger commands.
In case of the former, you can hold CTRL+SHIFT when VoiceAttack starts, and you'll get a "VoiceAttack Load Options" dialog; There you can check "Disable profile initialization commands (this session only)", which will stop any commands from running when your profile loads.
Before debugging your existing command, make sure you set up a "Stop All Commands" hotkey:
Click
, click the "Hotkeys" tab, and look for "Stop All Command Hotkey"; If there is no key assigned, or you wish to change it, click "..." to the right of "Stop All Command Hotkey", press the key or key combination you wish to assign(make sure "Enable stop command hotkey" is checked), then click "OK", clock "OK" at the bottom of the "Options" window to confirm.
Now, when a command goes haywire, you can press that key(combination) to stop all commands.
Personally I like to have a spoken command that does this as well; You can create a command within your profile that solely contains the "Stop Processing All Commands" action(Other > VoiceAttack Action > Stop Processing All Commands), speaking it should also stop all running commands.