/dev/sdb not detected anymore?

[Peter Teoh <htmldeveloper@gmail.com>]

I just built my 2.6.32-rc2 (from linus-git) yesterday, and repeated
today again, starting from "make mrproper", and consistently both
version cannot detect my /dev/sdb, which is the second SATA harddisk.
 The first SATA is detected as follows in dmesg:

    742 [    4.595949] scsi 2:0:0:0: Direct-Access     ATA
ST3500630AS      3.AA PQ: 0 ANSI: 5
    743 [    4.596116] sd 2:0:0:0: [sda] 976773168 512-byte logical
blocks: (500 GB/465 GiB)
    744 [    4.596213] sd 2:0:0:0: [sda] Write Protect is off
    745 [    4.596216] sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
    746 [    4.596258] sd 2:0:0:0: [sda] Write cache: enabled, read
cache: enabled, doesn't support DPO or FUA
    747 [    4.596467]  sda: sda1 sda2 sda3 sda4 < sda5 sda6 sda7 sda8 sda9 >
    748 [    4.674607] sd 2:0:0:0: [sda] Attached SCSI disk

And from sg_inq:

standard INQUIRY:
  PQual=0  Device_type=0  RMB=0  version=0x05  [SPC-3]
  [AERC=0]  [TrmTsk=0]  NormACA=0  HiSUP=0  Resp_data_format=2
  SCCS=0  ACC=0  TPGS=0  3PC=0  Protect=0  BQue=0
  EncServ=0  MultiP=0  [MChngr=0]  [ACKREQQ=0]  Addr16=0
  [RelAdr=0]  WBus16=0  Sync=0  Linked=0  [TranDis=0]  CmdQue=0
  [SPI: Clocking=0x0  QAS=0  IUS=0]
    length=96 (0x60)   Peripheral device type: disk
 Vendor identification: ATA
 Product identification: ST3500630AS
 Product revision level: 3.AA
 Unit serial number:             9QG14T5Z

But the second SATA (identical in type/model) is not detectable.
Upon rebooting to my previous 2.6.31 kernel version, it became
detected and usable - absolutely nothing else is touch.   So what is
it in the latest kernel which is giving the problem?

Can someone help me out?

THank you very much :-).

-- 
Regards,
Peter Teoh