>On 1.3 I get these messages during SCSI probe:
>
>ahc0: target 2 synchronous at 10.0MHz, offset = 0xf
>probe(ahc0:2:0):  Check Condition on opcode 0x0
>    SENSE KEY:  Soft Error
>     ASC/ASCQ:  ASC 0x5d ASCQ 0x00
>     FRU CODE:  0x31

/*               
 * From File: ASC-NUM.TXT
 * SCSI ASC/ASCQ Assignments
 * Numeric Sorted Listing
 * as of  5/12/97
 *  
 * D - DIRECT ACCESS DEVICE (SBC)                     device column key  
 * .T - SEQUENTIAL ACCESS DEVICE (SSC)               -------------------
 * . L - PRINTER DEVICE (SSC)                           blank = reserved
 * .  P - PROCESSOR DEVICE (SPC)                     not blank = allowed
 * .  .W - WRITE ONCE READ MULTIPLE DEVICE (SBC)
 * .  . R - CD DEVICE (MMC)
 * .  .  S - SCANNER DEVICE (SGC)
 * .  .  .O - OPTICAL MEMORY DEVICE (SBC)
 * .  .  . M - MEDIA CHANGER DEVICE (SMC)
 * .  .  .  C - COMMUNICATION DEVICE (SSC)
 * .  .  .  .A - STORAGE ARRAY DEVICE (SCC)
 * .  .  .  . E - ENCLOSURE SERVICES DEVICE (SES)
 * DTLPWRSOMCAE        ASC   ASCQ  Action  Description
 * ------------        ----  ----  ------  -----------------------------------*/

...

/* DTLPWRSOMCAE */{SST(0x5D, 0x00, SS_DEF,
                        "Failure prediction threshold exceeded") },

Essentially your drive is telling you that it believes it is going bad.

--
Justin