Kein Zugriff auf Website aus Intranet möglich!

Hello,

i have the following problem: i`ve pubished a website under a XP
workstation an d IIS 5.0. Every works fine with local access. BUT ...
access by Ethernet from another pc in the same domain doesn`t work
(Error: no Authzorization to view page)!
By default the option "Anonymous Access" is set under Properties of
Directory Security with the user IUSR_.
I=B4ve also tried it with "Integrated WIndows-Authentification" - the
same result! Everything works fine with local access - no access by
inranet...

Could anybody help me further???

I`ve tried the same under Windows Server 2003 and IIS 5.0 two years
ago and everything worked fine...

Thanks for giving me suggestions,
Maigo