Is my WD Caviar Blue failing? (WDC WD5000AAKX-001CA0)

For OLDPCMAN

While looking around I saw your post which is probably unrelated to my problem

BUT googling around I found

a) This test code is unknown even to WD (see http://community.wdc.com/t5/Desktop-Portable-Drives/WD1003FBYX-DLGDIAG-5-20-Error-0229-Missing-Test-Tracks/td-p/539436).

b) This error at least in two instances wasn’t because of the disk but because of the SATA controller

c) WD offerred an RMA return at least for RayeR in the aforementioned post only 3 weeks ago

I am probably not the most experienced person to answer your question but why not call technical support, while running a few more tests using tools like HD Tune Pro, or Hard Disk Sentinel as suggested before?