wsdl, disco not found or 'You are not authorized to view the page'

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Hi all
I created a custom web service, generated XXwsdl.aspx, XXdisco.aspx and
copied them to SP server. I can see the webservice while adding Web
Reference. But the system showed the classical error msg 'DISCO, wsdl, XML
element not found etc.' I researched and added 'validate=true' in
<httpHandlers><add verb="*.asmx"in machine.config(v1.x) and
web.config(v2.x). Now I try and get 'You are not authorized to view this
page' after I enter my SP uid and pwd. I have the Admin rights on the
account. Actually, I find these 2 error messages on consecutive tries.

Anybody got any ideas, pls share.

Thanks