It is probably indicating that parts of the drive are bad, however you may have reasonably large amount of usable space. I would send it back ASAP, you aren't going to be happy if you think you saved a file only to realize you can't read it back again or a game or program crashes at the worst moment!
E-mail WD the same info and I bet they will give you an RMA right away. Sometimes S&!t happens, got to deal with it sooner than later!
Could try TestDisk, it's free, perhaps the MBR is bad and repairable, but I wouldn't bother on a new drive! http://www.cgsecurity.org/wiki/TestDisk