I upgraded to Mountain Lion last night. Most everything checks out. However my iTunes library is on a 3TB Western Digital My Book Studio (gen 1). It was working perfectly on Lion. I have the latest firmware and WD software. Here are the things I have tried:
Cabling: Unplugged Firewire, Replugged Fireware. Unplugged Power, Replugged power, Tried USB, Back to Firewire.
Checked Firmware Updater: Latest firmware is currently installed
ReAuthorized Itunes. iTunes media folder was blank. I set it back to the folder used on my external. It dropped/unmounted in the middle of the iTunes Library updating. it didnt copy anything, it just reprocessed alot of artwork.
Sleep Setting: Used Smartview (WD software) to set sleep to 30 minutes, 90, never, etc... and it will randomly disappear/unmount in seconds or 5/10 minutes.
As of right now after the iTunes changes, its staying connected. But my morning it may disappear again. What is odd is that even though it disappears from my desktop as a connected drive, the WD Smartview will see the drive still connected and powered on. I can there choose an option to "mount" the drive. Very odd.
Is anyone still having this problem? If so, have you tried any of the above? I want to be careful to mess up my carefuly organized library, especially since iTunes manages the library. I dont want to cause a mass recopy/move.
As a side note, my Lacie Network Max 4TB drive is staying perfectly connected and my Time Machine backups are incrementally proceeding. I have not been asked to start a brand new back up. Additionally, I only had to re-enter my user login for my iMac's backup space I created. Historically, that was the drive that was the most troublesome when I upgraded from SL to Lion.
Thanks in advance.