SharePoint Designer 2007: "Server returned a non-specific error when trying to get data from the data source"

another lession learned: SharePoint Designer 2007: "Server returned a non-specific error when trying to get data from the data source"


I was baffled by this problem for hours when I tried to do dataview from a XML source.
 
google search yeild some clue about auth, ip address.
 
The problem I got is that I used http://192.168.18.18/mkselearning instead of http://mkssp3/mkselearning
 
use the http://servername/mysite URL fixed the problem