Macbook pro 13' running 10.5.8 has intermittent issues with usb 2.0 mass storage drives but not jump drives. Here is the issue, my gf just got a brand new mac book pro 13'. This is great for her no more asking to use my unibody macbook. She plugs in the drive i have used for a very long time with my mac my pac etc with not a hint of issue. The drive shows up copy's stuff off ok. However when it came time to return the data back to the drive it gets about 10% through and just hangs. Here is what i have done I first thought ok might need a re-boot no luck fixing it Then i went with the ok i will check her disk for issues. This is a 3 day old mac book by the way. I found random permissions errors with quick time which has never been run. After the fix the issue goes away for that boot. The issues seems to come back after a re-boot or so. I go ok enough of this i format the mac with the system disk, then i update to the latest updates from apple. plug in the drive and still having issues. Run the permissions repair same issues exactly format to format. I have also run the deep test off the system disk the machine checks out through that so i have ruled out ram on her system as a possible culprit. I am at a loss on this machine I have gone so far as to format the external drive replace the data from my network server and try that. Still no luck. On my box there is no issue it time machines great it copy's data like a usb 2.0 drive should.