I have a new 13" 2.3 i5. It's terrific. The 320 GB drive was a bit on the small side, so I swapped it for a 750 GB 7200 RPM Seagate. All good, but it creates vibration in the chassis that drives me nuts (no pun intended). Question: Would a 500 GB 7200 RPM drive solve or reduce the vibration? Or do I have to stick with a 5400 RPM drive? (Switching to SSD is not an option.) Thoughts and experiences welcomed.