On my laptop (HP nx 6125) the livecd and livedvd both fail. Both disks
can be mounted under Fedora Core or an existing hard-disk installation of
Scientific Linux. The LiveDVD is known to boot correctly on one
of my systems (HP xw 9300 workstation). However, on the laptop both
versions fail.

The boot process works up to here:

setup union on /union
looking for data modules

[ Then the system waits a long time ]

waiting for USB devices, max 9 seconds
[ various USB hardware messages ]
creating /dev entries for block devices
Fatal error occured - Data for LiveCD not found. Are you using SCSI?

[ No, I'm not using SCSI ]

Then I get dropped into a shell.

I then tried to create /tmp/disk and
mount -t iso9660 /dev/hdc /tmp/disk

I get the following error messages:

hdc: media error (bad sector); status = 0x51 { DriveReady SeekComplete Error }
hdc: media error (bad sector): error = 0x30
ide: failed opcode was 100
ATAPI device hdc:
  Error: Medium error -- (Sense key=0x03)
  (reserved error code) -- (asc=0x02, ascq=0x00)
  The failed "Read 10" packet command was:
  "28 00 00 00 00 10 00 00 01 00 00 00 00 00 00 00"
  end_request: I/O error, dev hdc sector 64
isofs_fill_super: bread failed, dev=hdc, iso_blknum=16, block=16

Can anyone help? Is there a magic boot option that can save the day?
This is particularly puzzling because the disk is not bad, and the
kernel and initrd (or initramfs or whatever it is) load ok, so why
the block read error at this point?

To give an idea of my hardware, here is the output of lspci:
[prw@ceiriog ~]$ /sbin/lspci
00:00.0 Host bridge: ATI Technologies Inc RS480 Host Bridge (rev 01)
00:01.0 PCI bridge: ATI Technologies Inc Unknown device 5a3f
00:04.0 PCI bridge: ATI Technologies Inc Unknown device 5a36
00:05.0 PCI bridge: ATI Technologies Inc Unknown device 5a37
00:13.0 USB Controller: ATI Technologies Inc IXP SB400 USB Host Controller
00:13.1 USB Controller: ATI Technologies Inc IXP SB400 USB Host Controller
00:13.2 USB Controller: ATI Technologies Inc IXP SB400 USB2 Host Controller
00:14.0 SMBus: ATI Technologies Inc IXP SB400 SMBus Controller (rev 11)
00:14.1 IDE interface: ATI Technologies Inc Standard Dual Channel PCI IDE
Controller ATI
00:14.3 ISA bridge: ATI Technologies Inc IXP SB400 PCI-ISA Bridge
00:14.4 PCI bridge: ATI Technologies Inc IXP SB400 PCI-PCI Bridge
00:14.5 Multimedia audio controller: ATI Technologies Inc IXP SB400 AC'97
Audio Controller (rev 02)
00:14.6 Modem: ATI Technologies Inc ATI SB400 - AC'97 Modem Controller (rev 02)
00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron]
HyperTransport Technology Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron]
Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM
Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron]
Miscellaneous Control
01:05.0 VGA compatible controller: ATI Technologies Inc ATI Radeon XPRESS
200M 5955 (PCIE)
02:01.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5788 Gigabit
Ethernet (rev 03)
02:02.0 Network controller: Broadcom Corporation BCM4318 [AirForce One 54g]
802.11g Wireless LAN Controller (rev 02)
02:04.0 CardBus bridge: Texas Instruments PCIxx21/x515 Cardbus Controller
02:04.2 FireWire (IEEE 1394): Texas Instruments OHCI Compliant IEEE 1394
Host Controller
02:04.3 Mass storage controller: Texas Instruments PCIxx21 Integrated
FlashMedia Controller
02:04.4 Class 0805: Texas Instruments PCI6411, PCI6421, PCI6611, PCI6621,
PCI7411, PCI7421, PCI7611, PCI7621 Secure Digital (SD) Controller

Peter