Openvz will no longer be supporting RHEL5 kernel as of October.
As of today we will be upgrading any RHEL5 kernel's to RHEL6. This only covers older servers:
This is to announce that RHEL5 based OpenVZ kernel branch will reach End Of Life in October, 2014, and will no longer be supported thereafter. There is no guarantee for any RHEL5 kernel updates after the given date, so we urge everyone to migrate their systems to RHEL6-based kernels.