OK, this is working from within a chroot jail, from the live cd, so I must assume there is something off in my configuration.

In /etc/resolv.conf, I have:

search asgard
nameserver 192.168.1.1

This appears to be the same as the live cd.
Additionally, as this is occurring only with certain dependencies (most things download and install just fine), I'm not sure where the issue is stemming from.