I have recently updated my stock Fujitsu 120GB drive with Seagate 500GB 5400.6 drive (ST9500325AS) Now, I am having several problems, the first and most bugging is that every other second I see the beach ball. Opening a new finder window, system preferences, just about anything slows the system down to a crawl. Infact, even typing this leads to a pause of 1 second or two. Second, i have tried using the disk utility to verify the volume. It gives an error before verification is complete. When using the installer disk to repair the disk, it completes successfully but later on when verifying again (even within the same installer disk utility it gives the same error) So, I was wondering is the error with my hard drive or a faulty installation of OS X. I had upgraded my RAM some time ago to 4GB OWC generic brand. Could the RAM be messing up. With Fujitsu, I used to have problems watching movies and TV shows (even regular lo-def files) but with this, it is much worse. Any idea on what to do??