After a call to HP, there seems to be a solution present.
Apparently it's a known issue on these boxes, when one is using the open source IPMI, instead of the HP OpenIPMI.

The resolution was to install HP OpenIPMI. The full description is below:

Quote

DESCRIPTION
On an HP ProLiant ML350 G5 server configured with a single processor, if
the HP System Health Application and Insight Management Agents for Linux
are installed without the HP OpenIPMI (hp-OpenIPMI) device driver
loaded, a console message is displayed indicating that there is a
problem with the system fan and that the server will sh  ...