mIRC 7.17
Windows XP SP3

Set a Lock Password for mIRC - Hold CTRL while minimizing - when trying to maximize it, it asks for the password. Enter the password and bring back mIRC.

Load the Script Editor then CTRL minimize mIRC ( not the Script Editor ) - You cannot access the Script editor without the password.

Now, this is the bug, Tools -> Options -> Script Editor -> Options -> [CHECK] Show on Desktop -> Click Ok -> Restart the Script Editor -> CTRL minimize mIRC ( not the Script Editor ) the Script Editor is still open.

I believe the Script Editor should not be available under when mIRC itself was CTRL minimized.

If we consider that the "show on desktop" feature is a basic one like it's only supposed to show the editor on the taskbar (on the desktop ?), then it's probably a bug since with that in mind, you don't want anyone to access something related to this instance of mirc.
However, if you see the feature like the editor is sort of another program, a standalone editor, then you might want to be able to use the editor whatever the mirc's state (locked).

Since it doesn't really make sense to lock mIRC and still want to be able to use the editor, I think too that this should be "fixed", it's unlikely that the behavior is intentional, rather a case that never happened so far