ssh-key weakness - test your keys day in debian/ubuntu

is better to check all your ssh keys on all servers , and update the ssh/ssl packages too
you key might be insecure

http://wiki.debian.org/SSLkeys

http://daviey.mooo.com/ubuntu/weak-ssh-key.html

wget http://security.debian.org/project/extra/dowkd/dowkd.pl.gz

gunzip dowkd.pl.gz
perl dowkd.pl file ~/.ssh/authorized_keys2