Comment 25 for bug 429370

#23

<i>The Diffie-Hellman prime sent by the server is not acceptable (not long enough).</i>

This maybe a bug (or a high-security feature) of gnu-tls library, for details see:
http://lists.shmoo.com/pipermail/hostap/2008-November/018701.html,

and for a workaround you can try newer version of gnu-tls (in this location are packages for ubuntu-ftp.ubuntu.com/ubuntu/pool/main/g/gnutls26/) or manual hack of the source according this: http://lists.gnupg.org/pipermail/gnutls-dev/2003-September/000517.html.