HP Proliant ML 150 G5 - "Boot Fail!" only after Power Outage.

I am trying to help with a HP Proliant ML 150 G5, that occasionally shows "Boot Fail! Please Insert Boot Media in selected Boot Device".  It only does this after a Power Outage.  Otherwise you can shut it down or re-boot as often as you like.  When you get the error you have to hit F6 (or whatever Function Key brings up the Boot Device screen) choose the Local Disk, and you are good from there.

We origionally ruled out the CMOS battery as it appears to retain it's other settings & Date/Time.

Any suggestions or similar experiences would be apprecitated.

Thanks,

Pat