From a support perspective, the C1100 model is not supported with ESXi 5.5. I'm not saying that this is the root cause of this issue, but this could certainly be related and you may want to re-consider using v5.5 in a production environment.
Assuming the installation media is ok and the issue still occurs, you would now need to check whether a firmware update or a custom image with updated drivers (e.g. mass storage drivers) can help. Other than this, it should work to re-install ESXi 5.1 on the host, selecting the option to preserve existing VMFS datastores.
André