guju, all,
no, there is NOT any instance where your code (the one you want to send to clients thru http) should be hidden
sensitive informations should be placed elsewhere - you have to separate your code (separate logic from business from presentation - or separate engine, database accesses, and user interface)
because anything you make public to the web can be stolen - whatever tricky technique you found
hiding (trying to hide) your source code doesn't protect you, it's just stupid and not fair to all users that have learnt like you did, by reading other's source code