>Once the Web Service registered, the same code will fail on the GetNews() method or any other method as they require the proper login authentication to reside in memory. Login() will work but any additional call to any other methods will fail. Using the COM approach, the same code works as is. I mean the same code but the instantiation of the WS differs, of course.

yes, I know that. A couple of months ago I saw that when I first tried to access UT's WS from .Net. Haven't you found any property that you may need to set in that add-in that Martín had mentioned?