Hi, I just received and installed a 1GB memory stick from OWC and the system profiler shows this: Size: 1 GB Type: DDR2 SDRAM Speed: PC2-4200U-444 Status: OK Does the 444 stand for the mhz? Shouldn't the memory be 533 mhz? How do I test to make sure it is the correct speed? Thank you for your help. P.S. BTW It's my first MAC and its great!