The remote host is missing an update to ca-certificates announced via advisory DSA 2299-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202299-1

An unauthorized SSL certificate has been found in the wild issued the DigiNotar Certificate Authority, obtained through a security compromise with said company. Debian, like other software distributors, has as a precaution decided to disable the DigiNotar Root CA by default in its ca-certificates bundle. For other software in Debian that ships a CA bundle, like the Mozilla suite, updates are forthcoming. For the oldstable distribution (lenny), the ca-certificates package does not contain this root CA. For the stable distribution (squeeze), the root CA has been disabled starting ca-certificates version 20090814+nmu3. For the testing distribution (wheezy) and unstable distribution (sid), the root CA has been disabled starting ca-certificates version 20110502+nmu1. We recommend that you upgrade your ca-certificates packages.