Esta é a resposta que recebi do suporte do smartmontools:
Regarding the self-test log: Broken self-test logs are a typical drive firmware flaw which cannot be fixed by smartmontools. A quick search on my archive of smartctl outputs show same behavior for: ADATA_SP300 ADATA_SP550 ADATA_XM11_128GB Corsair_Force_GS INTEL_SSDSA2VP020G3 INTEL_SSDSC2CW180A3 INTEL_SSDSC2KW240H6 MAXTOR_STM3160215AS Mushkin_MKNSSDCL60GB-DX SAMSUNG_SP0842N SanDisk_SDSSDX240GG25 Seagate+ST3200826AS Seagate+ST94813A
Acho que também podemos adicionar WDC WDS120G2G0B-00EPW0 a essa lista.