User Mapping failing for SharePoint Integration..

HI

I am trying to integrate Sharepoint document library with SAP KM as WebDAV repository but stuck with the single sign on issue using User Mapping. It gives authorization error when try to access the library via KM and even creating a simple URL iview with the sharepoint URL gives Authorization issue. Not sure what could be the issue here. Seems like its failing somewhere at the IIS proxy level.

The versions are EP 7.0, Sharepoint 2007, IIS6

All the pre-reqs are done at the KM level (HTTP system, WebDAV Manager, WebDAV System, ). Also have defined the user mapping in the User's profile level. But still cant get rid of the authorization issue.

Any pointer is really appreciated.

Thanks

Sandip