Check if memory is on the compatibility list.
Use latest service pack for the os.
Disable multi core processor in the bios.
Regarding the Orange blinking LED:
Updating the board firmware:
The recommended upgrade method, if not updating a hot-swap controller (HSC), is:
Reboot, and verify BIOS settings
The recommended method with an HSC(backplane) is:
Reboot, and verify BIOS settings.
Other than this, next steps will be to verify the sel log and verify the release notes of the firmware if there is anything mentionned.
Hope these are useful,