Well I'm a bit perplexed. I have a 4 GB SONY MICRO VAULT I have used for the past few months with my work PC. I have recently purchased a Mac Book Air (Fully updated Leopard 10.5) and decided to use my MICRO VAULT with it as well. When I plug the micro vault into the MacBook Air the computer does not recognize the drive. The computer simply acts like there is nothing in the USB plug at all. I then decided to try and use it on my Mac Mini Core2Duo (Fully updated Leopard 10.5) and it also failed to recognize the drive. Tested it again and my work PC still recognizes the drive fine. Any suggestions or recommendations on what may be the cause or solution?