But it NEED bitcoin 0.6.4 or higher! You need compile it form sources https://github.com/bitcoin/bitcoin
FWIW, that git tree is for 0.7 (not stable yet). For 0.6.4, you need http://gitorious.org/bitcoin/bitcoind-stable/
0.7 is marked as rc1 so it is close to stable for me
I have backup of backup of backup of my wallet, so I can be a guinea pig
for me v4 works with bitcoind 0.6.3 without any errors.
maybe it depends on bintcoind running on the same, or a different machine. i use different VMs for p2pool, bitcoind and namecoind. All machines running Ubuntu 12.04.