Pending and Uncorrectable sectors are sectors that the drive had data on them but was unable to read the sector the last time you tried to read it. If you did not write to every sector yet on the drive this could have been from the factory initialization which is the same case I was talking about that I was able to fix with a full drive write (same manufacturer as well - WDC black in my case). However if you did write a sector and the drive can not read it any more it could be a problem with the heads or possibly a just media defect. Do you scrub your zfs?
Edit: I know I was a little short on this. I am just about to leave for work. I will try to add some later.
Well, time for a new disk, methinks. Zeroed it out with 'dd' using sysrescuecd. Rebooted win7 and reran CDI. The uncorrectable and pending went away, The bad news: the reallocated sector count is 140!