Comment # 1 on bug 964998 from Takashi Iwai

Just to be sure, it's not a USB keyboard but the built-in PS2 one, right?

Also, when this happens, it appears only with the built-in keyboard, not with
an externally connected one?

About the memory: what do you mean exactly "my physical memory consuming 2GB"? 
Did you actually remove the memory physically, or pass some kernel boot option
to limit the size?