Reloading MXO-externals in max: Delete-Undo doesn't reload

I am trying to develop c-externals in xcode. I can compile them and use them in max 5, but if I change my c-code and compile it, I need to restart MAX5 entirely before the changed MXO-object is loaded into Max5. If i just use delete-undo (as I have done with java-development) the old object is loaded. This is also the case if I delete and create a new instance.

Is this really how it works. Or can it be worked around. It is very difficult developing (and learning) when you cannot test the object in a faster way.

Anyone having the same problem - or even better: a solution?

-Sune