Can't figure out the contradictory HDD LifeGuard Diagnostics data and also, Model Number

I am a more or less happy user of 3 WD HDDs. I installed and ran the LGD test, which keeps showing that it can not complete test for the 1.5 Tb drive. Well, I have to get it repaired or changed. However, it also shows that the other two drives passed the Smart Scan test, but when clicking on the test result multiple errors appear on both the 2 Tb and the 3 Tb drives, and the green checkmark of “pass” turns red (fail). Now I do not understand: all my brand new drives are failing? chkdsk /f /r /x found problems only for the 1.5 Tb HDD so it is the only faulty. I do not understand why the other two drives show the following problems.
I registered at WD webpage and tried to contact customer service but I simply can not find the Model Number for my drives. Properties (LifeGuard Diagnostics) tell the serial number and that these are all WD Ext HDD Model 1021, but nothing else! I can’t find this by search at WD’s support page and thus I can’t even post my issue there.
So, the errors of these disks:

Detailed errors for all the drives:

Power-off retract count ID E4 Warranty 1
Unknown ID 64 Warranty 1
Multi Zone Error Rate ID C8 Warranty 1
UntraDMA CRC Error Rate WID C7 Warranty 1
Multi Zone Error Rate ID C8 Warranty 1
Multi Zone Error Rate ID C8 Warranty 1
Multi Zone Error Rate ID C8 Warranty 1
Raw Read Error Rate ID 1 Worst 1 Warranty 1

Drive 1.5 Tb (first test):
Test Option: QUICK TEST
Model Number: WD Ext HDD 1021
Unit Serial Number: [Deleted]
Firmware Number: 2021

Capacity: 1500.30 GB
SMART Status: PASS
Test Result: FAIL
Test Error Code: 06-Quick Test on drive 2 did not complete! Status code = 07 (Failed read test element), Failure Checkpoint = 97 (Unknown Test) SMART self-test did not complete on drive 2!
Test Time: 10:05:16, March 30, 2014

Drive 1.5 Tb (2nd test):

Test Option: QUICK TEST
Model Number: WD Ext HDD 1021
Unit Serial Number: [Deleted]
Firmware Number: 2021

Capacity: 1500.30 GB
SMART Status: PASS
Test Result: FAIL
Test Error Code: 06-Quick Test on drive 2 did not complete! Status code = 07 (Failed read test element), Failure Checkpoint = 97 (Unknown Test) SMART self-test did not complete on drive 2!
Test Time: 10:05:57, March 30, 2014

Drive 1.5 Tb (3rd test):
Test Option: QUICK TEST

Model Number: WD Ext HDD 1021
Unit Serial Number: [Deleted]
Firmware Number: 2021
Capacity: 1500.30 GB

SMART Status: PASS
Test Result: FAIL
Test Error Code: 06-Quick Test on drive 2 did not complete! Status code = 07 (Failed read test element), Failure Checkpoint = 97 (Unknown Test) SMART self-test did not complete on drive 2!
Test Time: 10:07:03, March 30, 2014

Drive 2.0 Tb (first test):
Test Option: QUICK TEST

Model Number: WD Ext HDD 1021
Unit Serial Number: [Deleted]
Firmware Number: 2021

Capacity: 2000.40 GB
SMART Status: PASS
Test Result: PASS
Test Time: 10:12:37, March 30, 2014

Repeating the test on the same drive now gives fail:
Test Option: QUICK TEST

Model Number: WD Ext HDD 1021
Unit Serial Number: [Deleted]
Firmware Number: 2021
Capacity: 2000.40 GB

SMART Status: FAIL
Test Result: PASS
Test Time: 10:37:57, March 30, 2014

Drive 3.0 Tb (first test):
Test Option: QUICK TEST

Model Number: WD Ext HDD 1021
Unit Serial Number: [Deleted]
Firmware Number: 2021
Capacity: 3000.59 GB

SMART Status: PASS
Test Result: PASS
Test Time: 10:57:36, March 30, 2014

Hello,

Do you have these drives connected to the motherboard or in some kind of external enclosure?

You can find the model number on the label that’s on the drive or with the serial number in the following link:

http://websupport.wdc.com/warranty/warrantycheck.asp?custtype=end

These are standalone external drives connected through HUB. I bought a new one now, a 2 Gb drive. Yesterday it was mostly green and today it started to develop several red items in the Data Lifeguard diagnostics. I just don’t understand what each item means and how to read it. For instance, the helpfile says: “An impending degrading or faulty condition is indicated when the calculated Attribute Value becomes less than or equal to its corresponding Attribute Threshold value.” This is contradictory, because all values and thresholds are zero always except for PZT failure detection which has 100 as a threshold but the estimated value is always 0. So, I do not understand how to read these data, why there are increasing numbers of red items even in a 2-day old drive. Can anyone tell me if it is to worry or not to worry, or this is a bogus report and CHKDSK is the appropriate one etc…?

Thanks