Seven......
I experience that same exact issue with a brand new WD20EARS with jumpers on. Here is the thread i was asking if someone could help me out.http://lime-technology.com/forum/index.php?topic=8506.0
All the errors start showing up about 60% into the post read phase, the process just hang from there and would not proceed, so i stop it.
I really cannot pinpoint what the problem was, cause no one chimed in. But from looking at the syslog it might have been some kind of connection issue of some sort be it data or power.
Anyway i restarted the preclear process and it completed the process fully and the drive was ok as far as in know how to interpret the results.
Good luck....