Mas ve volbe Boot -> User Access Level nastaveno Full Access (viz. manual strana 3-32)..?
Vyzkousel bych postupne vzdy po jednom kousku tech RAM...
http://forum.crucial.com/t5/Ballistix-Performance- Memory/Asus-P7P55D-only-registering-half-the-insta lled-RAM/td-p/113292