unbound is extremely slow

So I have unbound running in a vnet jail. Doing a lookup with `host` is
pretty responsive, but Chromium's lookups are extremely slow (taking around
30 seconds to resolve). I'm running pretty much a stock config. I've tried
turning off DNSSEC, but that doesn't help any. I have num-threads set to 4,
though I have 8 cores on this box. I've pasted my config below.

Thanks,

Shawn

server:
        username: unbound
        directory: /var/unbound
        chroot: /var/unbound
        pidfile: /var/run/local_unbound.pid
#auto-trust-anchor-file: /var/unbound/root.key
        logfile: /var/unbound/unbound.log
        log-time-ascii: yes
        log-queries: yes
        verbosity: 2
        interface: 0.0.0.0
        interface: ::0
        access-control: 0.0.0.0/0 allow
        access-control: ::0/0 allow
        prefetch: yes
        num-threads: 4

include: /var/unbound/forward.conf