This bug is not limited to only when over 4.2 GB RAM is utilized, I see this bug happening any given time. It will never stay in sleep mode anytime over 4.2 GB RAM is utilized ever: not the first, second, third time, or ever that I have tested. I am now using a new BIOS/firmware (1.8) and I see that piece of this bug remains.
Additionally it resumes from sleep mode in the scenario that under 4.2 GB RAM is utilized, in that scenario it completes the sleep mode the second (next) time the sleep state is invoked even when the idol timer is invoking the sleep state.