I think wizards for creating web services provided by WTP are bad solution and our way of extending them brings lots of problems we have to deal with. I suggest to write new wizards for creating web service. As it happened in the case of 'Create a Sample Web Service' which is fully under our control and is pretty simple and works well. New wizards can of course reuse code from 'Create a Sample Web Service' since there are many same or similar steps.