[tor-relays] Upgrading to 0.2.3.4 on Debian

I setup a relay to support the cause, but also as a means to learn about Linux - still a long way to got on the latter, and so this question:

I run aptitude regularly, and my sources.list includes "deb http://deb.torproject.org/torprojects.org squeeze main" but there are no updates coming through for tor beyond 0.2.1.29-1 on my ppc platform.

Should there be, or should I be doing something else to get to 0.2.3.4? Am I even asking the right question?

Thanks...