vzpkgcache seems to have been broken with latest CentOS-5.3 upgrade. Below is notes to fix:
cd /usr/share/vzpkgtools/vzrpm44/lib/python2.4/site-packages/rpm
cp /usr/lib64/python2.4/site-packages/rpm/_rpmmodule.so .
Edit the file /usr/share/vzpkg/cache-os line 154, append:
mkdir -p $VE_ROOT/var/lib/yum/ || abort "Can't create /var/lib/yum"
Edit the file /usr/share/vzpkg/functions line 20, change to:
VZLIB_SCRIPTDIR=/usr/lib64/vzctl/scripts
Run to updatee the cached template:
vzpkgcache centos-5-x86_64-minimal
Reference: wiki.openvz.org