When working on a solution which contains a web service project and a client project that calls the web service, typically you will perform changes in the webservice definitions (changing/adding methods and signatures to the web service) which you would like to be shown in the intellisense and when compiling the client.
You would assume all you need to do is compile the webservice and publish it after the change and then right-click on the webservice web reference in the client project and do 'update web reference' and that's it.
But there seems to be problems with this method - as changes are still not reflected.
What i found to work is to 'rebuild' on the web service + publish it.
Then open the wsdl in a web broswer - see the actual change.
Then right-click on the webservice web reference in the client project and do 'update web reference'.
Then, republish the web service again.