Comment 1 for bug 254467

I think it's not a problem of vzctl, but probably some kernel bug.

However, I can confirm on a Hardy box, that "grep -i mhz /proc/cpuinfo" shows the same value on the hardware node and the virtual container (which is limited through CPUUNITS).

My understanding until now has been that the CPUUNITS would not change the reported CPU speed in the container(s).

Are you also using CPUUNITS to limit the cpu on both the Debian and Ubuntu HN?
What kernel versions are you using on the HNs ("uname -a").
The version of vzctl might also be interesting ("dpkg -s vzctl | grep Version:")