There is no reason it wouldn't get the *keystroke* you're sending to all, but that doesn't mean the WoW Macro is active (e.g. because ISBoxer Addon is not enabled, or did not fully export, etc) and operational (e.g. because something is overriding the binding ISBoxer assigned).

Try exporting manually on the second PC to be sure it doesn't complain about anything. Remember that if it doesn't say "Export successful" it's NOT fully exporting and you will need to resolve some error before it will.

And make sure the ISBoxer Addon is enabled in that window where nothing is working. ISBoxer Addon will ALWAYS say stuff in your chat window when it loads, and should also indicate what Character Set and/or Character is loaded.