Impending failure on new disk: still resyncing - what to do?

Installed a new 3TB Seagate ST3000DM001-1CH166 yesterday. I saw it start the Restriping before I went to bed and didn't check in again until I received a couple emails today, 16 hours after the initial drive replacement:

Detected increasing pending sector count[65528] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.

Here's the full log of relevant messages:

	Tue Apr 30 14:05:13 PDT 2013	Detected increasing uncorrectable errors[65528] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Tue Apr 30 14:05:10 PDT 2013	Detected increasing pending sector count[65528] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Tue Apr 30 12:55:58 PDT 2013	Detected increasing uncorrectable errors[65528] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Tue Apr 30 12:55:48 PDT 2013	Detected increasing pending sector count[65528] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Tue Apr 30 11:30:37 PDT 2013	Detected increasing uncorrectable errors[65528] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Tue Apr 30 11:30:27 PDT 2013	Detected increasing pending sector count[65528] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Tue Apr 30 11:26:27 PDT 2013	Detected increasing uncorrectable errors[65520] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Tue Apr 30 11:26:22 PDT 2013	Detected increasing pending sector count[65520] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Tue Apr 30 11:22:23 PDT 2013	Detected increasing uncorrectable errors[65528] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Tue Apr 30 11:22:13 PDT 2013	Detected increasing pending sector count[65528] on disk 2 [ST3000DM001-9YN166, W1F0RGDC]. This often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.
	Mon Apr 29 19:41:58 PDT 2013	RAID sync started on volume C.
	Mon Apr 29 19:40:36 PDT 2013	Data volume will be rebuilt with disk 4.
	Mon Apr 29 19:39:26 PDT 2013	New disk detected. If multiple disks have been added, they will be processed one at a time. Please do not remove any added disk(s) during this time. [Disk 4]
	Mon Apr 29 19:38:22 PDT 2013	System is up.
	Mon Apr 29 19:29:20 PDT 2013	Powering off device

I'm led to wonder how serious the "increasing pending sector count" is and if I've got justification for a return to Amazon as defective? Also I'm a bit confused because the SMART says the pending sector count is zero, if I'm reading it right. Here's the SMART:

SMART Information for Disk 4

Model:	ST3000DM001-1CH166
Serial:	W1F25VEW
Firmware:	CC24
SMART Attribute
Spin Up Time	0
Start Stop Count	3
Reallocated Sector Count	0
Power On Hours	23
Spin Retry Count	0
Power Cycle Count	3
Runtime Bad Block	0
End-to-End Error	0
Reported Uncorrect	0
Command Timeout	0
High Fly Writes	0
Airflow Temperature Cel	34
G-Sense Error Rate	0
Power-Off Retract Count	3
Load Cycle Count	3
Temperature Celsius	34
Current Pending Sector	0
Offline Uncorrectable	0
UDMA CRC Error Count	0
Head Flying Hours	130554120896535
Total LBAs Written	2254299683
Total LBAs Read	127872750
ATA Error Count	0

Can someone help me shed some light on this? I also want to know how urgently I need to replace this disk and if I should wait for all of the resync steps to finish or not. Since my volume is unprotected I don't want to screw it up. Also, should I wait for a replacement drive or go back to the 2TB that I just replaced?

It looks like the restriping phase is now done. The device LED shows Resync C: 3.1%. The Volume Settings page shows progress in the Recovery phase, which doesn't sound familiar to me:

RAID Configuration

Configuration: 	RAID Level X-RAID2, 4 disks	  
Status: 	Recovery 3% complete, Time to finish 508 hr 51 min, Speed 1031 KB/sec

RAID Disks:

Ch 1 : Seagate ST3000DM001-9YN166 [2794 GB]	2790 GB allocated			
Ch 2 : Seagate ST3000DM001-9YN166 [2794 GB]	2790 GB allocated			
Ch 3 : Hitachi HDS723030ALA640 [2794 GB]		2790 GB allocated			
Ch 4 : Seagate ST3000DM001-1CH166 [2794 GB]	

Thanks for any help!!