Often, this is more power than a USB port on a notebook computer can provide, especially as the drive ages. Also, the Passport does not have its own power supply and must get power to turn the platter motor and run the electronics from a USB port. If the WD software folder has an uninstaller, try running it. There are also recent reports here of WD software not playing well with Mac OS 10.9 Mavericks. Time Machine without any third-party backup programs is the least intrusive backup scheme.
WD's backup software is intrusive and, for me, slowed overall computer performance-including lockups-to the point I gave up on it.
However, if you installed the WD software that came with the drive, that could be part of the problem. Help me understand-the Passport has password protection separate from anything Mac OSX provides? Wasn't aware they were doing that.
