I have two EZIO8SA units. One direct from Simplehomenet and one through Smarthome.
Both of mine act diffently; than what you have observed.
The Smarthome unit; came with a 2412S PLM not the 2414S PLC with PLM firmware I got from Simplehomenet. Firmware sticker on PLM/PLC with PLM Firmware is. 2.4
My users guide for the 2412S says:
If the LED is on Steady. The PLM has detected en external EEPROM for storage of database links.
If the LED blinks six times. The PLM has not detected an external EEPROM and will use its internal EEPROM on the processor chip.
Both of mine with only the PLM and no EZIO8SA; the LED never blinks.
EZIOXX Utility as long as it can see the PLM shows all off on inputs and outputs.
With an EZIO8SA connected. It lights then briefly goes off, then back on steady.