OK, apparently that “Enter standby” message kept waking up my MBL because of the issue described in:
I had a huge daemon.log.1 with 300MB (mostly that stupid "cnid_metad[1919]: error in accept: Socket operation on non-socket " message) in /var/log … hence the RAMLOG service wasn’t used and ALL logging went directly to disk always waking it up from standby.
Once I removed the file and rebooted my MBL, ramlog was able to perform its duties … however, on this reboot I got tons of new cnid_metad-Errors filling up the ramlog-Ramdisk fast … 
Since I don’t need that useless Apple stuff at all, I used update-rc.d to remove netatalk from init.d and hopefully I’ll never see that error again.
