i just bought a hp pavilion zd8000. its got 512mb(two 256mbs) ddr2 sdram at speed of 400mhz. im thinking about buying a 1G or 512mb ram and replacing one of the rams with the new one but the one im buying is ddr2 sdram but 533mhz. does that mean my comptuer will be using the ram at the speed of 400mhz and there will not be a problem installing the ram?