Hate to necro an old thread but I just got done dealing with this on a few servers in our environment (including a DL380 G3).
To fix, first get 2 floppies. You'll need to use the ROMpak to flash the controller.
Aka the one that reads as:
**CRITICAL ** Options ROMPaq Firmware Upgrade Diskette for HP Integrated Lights-Out Management Controller
Download the ROMPaq.
Run it and let it format the 2 floppies.
Power off the server.
Set the dip switch (1) to disable the security.
Insert floppy 1.
Follow prompts until it is done.
Restart and you should see the F8 boot option for iLO.
Don't forget to flip the dip switch back.