Mike, I'm sorry that it hasn't been the magic bullet for you. I'm sure you have thought about it, but it might be worthwhile to try reformatting the the disk with the newst build of Disk Utility. Of course that woiuld wipe all your data.....
ALso, an update: I connected my 2tb Hitachi Touro to my Apple Extreme this morning and it has been merrily backing up all day via Time Machine. It's got about another six hours to go, but it is working. The real test will be over the next day or so to see if it continues to keep working....
I agree that 10.8.3 fixed the problem. However, in scanning the release notes I could not find a specific reference. The closest was 3TB relative to BootCamp. Seems odd that an issue this big was not specifically called out. Maybe Apple's attitude is that if it is never acknowledged there never was an issue!
Thanks. Yeah, I was thinking re-formatting might do it. However, I believe Apple says somewhere its not really a problem and that the drives will work. The only 'problem' I experience is sometimes they don't mount so I turn them off and on again. Otherwise they seem to work fine.
Both those big drives are were I keep my files archive and each one is a backup of the other in case one fails.
So I guess if it really bugs me I'll reformat with ML.
With thousands of computers in my Universities domain, we've run into this problem serveral times now. It is a Mountain Lion issue on some hardware, mostly MacBook Pros with SSDs and 10.8.5. It is less frequent with 10.8.4. If you downgrade to 10.8.3, it should fix the problem. We are waiting until we fully support Mavericks thus I can't confirm if it exits there too. Until then, the issue needs to be identified and fixed by Apple with an update to 10.8.5.
I'm attempting to migrate from a late 2009 iMac (comventional rotating disk) to a new MBP Retina with an SSD using a TM backup on a Newer Technology OWC EHD. Both computers are running the latest version of Mavericks. On the iMac Disk Utility gives no error messages, but this issue shows up when I run the MBP Disk Utility on the same drive.
So, I'm going to try the migration anyway. Hope I don't crash and burn.