The remote host is missing an update to fam announced via advisory DSA 154-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20154-1

A flaw was discovered in FAM's group handling. In the effect users are unable to FAM directories they have group read and execute permissions on. However, also unprivileged users can potentially learn names of files that only users in root's group should be able to view. This problem been fixed in version 2.6.6.1-5.2 for the current stable stable distribution (woody) and in version 2.6.8-1 (or any later version) for the unstable distribution (sid). The old stable distribution (potato) is not affected, since it doesn't contain fam packages. We recommend that you upgrade your fam packages.