Heres the output from hdparm v5.2 [couldn't find a binary of 5.3 for Redhat].
I ran hdparm -I /dev/hda

/dev/hda:



ATA device, with non-removable media

	Model Number:       Maxtor 6Y120L0                          

	Serial Number:      Y40QEKSE            

	Firmware Revision:  YAR41VW0

Standards:

	Supported: 7 6 5 4 

	Likely used: 7

Configuration:

	Logical		max	current

	cylinders	19	19

	heads		16	16

	sectors/track	63	63

	--

	CHS current addressable sectors:      19152

	LBA    user addressable sectors:      20000

	device size with M = 1024*1024:           9 MBytes

	device size with M = 1000*1000:          10 MBytes 

Capabilities:

	LBA, IORDY(can be disabled)

	Queue depth: 1

	Standby timer values: spec'd by Standard, no device specific minimum

	R/W multiple sector transfer: Max = 16	Current = 16

	Advanced power management level: unknown setting (0x0000)

	Recommended acoustic management value: 192, current value: 192

	DMA: mdma0 mdma1 mdma2 udma0 udma1 *udma2 udma3 udma4 udma5 udma6 

	     Cycle time: min=120ns recommended=120ns

	PIO: pio0 pio1 pio2 pio3 pio4 

	     Cycle time: no flow control=120ns  IORDY flow control=120ns

Commands/features:

	Enabled	Supported:

	   *	NOP cmd

	   *	READ BUFFER cmd

	   *	WRITE BUFFER cmd

	   *	Host Protected Area feature set

	   *	Look-ahead

	   *	Write cache

	   *	Power Management feature set

		Security Mode feature set

	   *	SMART feature set

	   *	FLUSH CACHE EXT command

	   *	Mandatory FLUSH CACHE command 

	   *	Device Configuration Overlay feature set 

	   *	Automatic Acoustic Management feature set 

		SET MAX security extension

		Advanced Power Management feature set

	   *	DOWNLOAD MICROCODE cmd

	   *	SMART self-test 

	   *	SMART error logging 

Security: 

	Master password revision code = 65534

		supported

	not	enabled

	not	locked

	not	frozen

	not	expired: security count

	not	supported: enhanced erase

HW reset results:

	CBLID- above Vih

	Device num = 0 determined by the jumper

Checksum: correct

Attached is the output from /proc/ide/hda/identify

Now looking at the output from hdparm -I [above] can't see if the problem is the unlock - doesn't look like the drive is locked to me.
Still the info will be in the relevant parts of the attached identify output.