In the end, we found out that this customer - without my knowledge - had actually bumped up their kernel with errata updates via the Red Hat Network. Once we reconfigured OFED and built a custom ISO, the driver was re-installed and this command now works quite well.
It is possible that the original poster of this thread has something other than the default, Red Hat/CentOS kernel (provided on DVD or ISO) and the Mellanox OFED drivers were not reconfigured and recompiled to support the kernel updates.
Symptoms do not present during the installation script, which makes this process more confusing - no errors of any kind. But once certain features are utilized then the problems begin.
If the kernel has any updates of any kind following Linux ISO or DVD installation, then Mellanox OFED must be reconfigured to support the new kernel and the resulting custom ISO must be mounted and used.