User.IsInRole is always FALSE

[Oliver Rainer]

Hi, I have the following problem...

Pre-requisites:
Installation of an Asp.net webservice on a IIS5 server (win2k). Anonymous
access is not allowed, only using windows authentication (intranet app),
webmethoda are using the Principalpermssion attribute
([PrincipalPermission(SecurityAction.Demand,
Role=@"DomainName\WindowsGroup...")]) for identification.

Result --> does not work

When I change the to [PrincipalPermission(SecurityAction.Demand,
name=@"DomainName\Windowsuser...")]) -> it runs fine

--> conclusion: IIS cannot determine if a user belongs to an AD group -->
IPrincipal.IsInRole(@"DomainName\WindowsGroup") is always FALSE!

I already found an article on the web
(http://www.kbalertz.com/kb_894432.aspx --> web dir is UNC share), but
didn't solved the problem...

Does anyone know more about this issue?

Thanks
Oliver Rainer