In my efforts to support IPv6 on my vservers, it threw me into using the "unstable" version of the linux-vserver patches. There are a few advantages to the latest code, not the least of which is IPv6 address support within your vservers. But it does bring me to highlight the need to keep your kernel vserver patches and the util-vserver package in parity.

I upgraded to version 2.6.31-vs2.3.0.36.23 (same deal under the currently current 2.6.33-vserver-2.3.0.36.30.4-r1 as well) and rebooted and lo and behold, all my vservers and my host system shared the same hostname. This was a peculiar problem but it is in fact related to the version of util-vserver you are running. This is not the first oddness I've seen from having them out of sync and I'm sure it won't be the last. Sure enough, upgrading my util-vserver to 0.30.216_pre2883 from 0.30.215 did the trick nicely. Reboot and you're back to normal operation.