You can run "xev" from a windowmaker terminal to check if your F7 key is still registering key press/release events. (That is not exactly the same situation as when you try to switch back to vt7, but you will see whether the key is active at all.)
Every key stroke from F1 to F12 triggers an event, but F7 and F9 do not fire anything. How do I ensure F7 and F9 are registered?
Regards, CN