exact same issue here. 1.5 TB device in external case. Problem doesn't occur under Mac OS X, so it cannot be due to bad cable or bad power supply. It's a really annoying bug that should be fixed!
** Changed in: ubuntu Status: New => Confirmed -- USB drive is randomly unmounted: reset high speed USB device using ehci_hcd https://bugs.launchpad.net/bugs/622494 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs