IIRC, there is a register in the ESCD that determines the appropriate gates for RAM, and sometimes that gets corrupt/conflicts after adding new hardware. When you removed a stick from your board, the other stick became unstable, indicating there was a problem with an invalid location. When you added the memory stick back in, the ESCD would be required to update itself because it found new memory, and thus had to remap the addresses, thus creating a brand new table that should be free of corruption. Happens all the time. However, if it happens again in the next few months, I would replace the battery.
Either that, or both your DIMMs were housed incorrectly. I see that
too
.
And remember, "Reset Configuration Data" is your friend, and "PnP OS Installed" is your enemy.
