Access denied in subdirectory


i have a problem configuring IIS6 to enable http downloads. I have a
subdirectory on Inetpub\wwwroot called download. There I put some
files (.exe and .dll) for downloading. I also registered MIME types
(.dll and .exe) as Application/octet-stream.

The download via Browser from the root of the download directory works
well but if I have a subdirectory (e.g. inetpub\wwwroot\download\test)
and put some files in there i get the following error message:
HTTP Error 401.3 - Unauthorized: Access is denied due to an ACL set on
the requested resource.

The access is anonymous with the local IUSR account. This account have
NTFS read permissions on the directory.

Has anyone an idea what's going wrong?