I would try going into BootROM and performing a FW update from there. You can look at this guide to get into BootROM, but instead of clearing the configuration, you can do an "Update Firmware" via XMODEM or TFTP (the Ethernet Port IP address can be set under SYSTEM CONFIGURATION).
Hope this helps,
Patrick: Thanks for you prompt response and good advice. I updated the firmware to the latest rev and that fixed the BootROM issue and it is now fully operational. The best part was that the configuration was saved, so once the firmware was updated, it was ready to go again. I've since saved the config files of the mutiple 550 units I have in case i need to restore them.
Once again thank you for you help in getting this fixed without having to RMA the unit, as it was 2 weeks past the warranty date!!