Soap Exception Error when calling ASP.NET Web Service from SAP

In one of my recents projects i had to call an ASP.NET Web Service from SAP.

Although i called the web service passing the corrects credentials i got SOAPEXCEPTION(Soap Fault Code 1) error

After searching several hours i found that when i configure the authentication mode of my application using Basic Authentication it work fine...

For more details about IIS authentication mode: http://msdn.microsoft.com/en-us/library/aa292114(VS.71).aspx