Thanks, everyone, for your input. You've given me a lot of good ideas
to pursue. Here's where I'm at today, so please bear with me.

I haven't been able to get makebootdisk to make a proper LILO boot
disk for me (maybe the files are too big?), but I managed to find an
old Syslink boot disk that I could boot with. I used this to get into
my system and create a new Syslink boot disk with my new kernel. I
can boot up my system NO PROBLEM with the Syslink boot disk.
Everything looks and functions as it should. But I don't want to be
relegated to booting off a floppy for the rest of my life...

So it looks like my hard drive itself is fine.

I then tried this:
lilo -u /dev/hda

followed by lilo and rebooted, but I had no luck.

I then used "hdparm" to see how linux sees my hard drive and got these
results:
hdparm -g /dev/hda

/dev/hda:
geometry = 4866/255/63, sectors = 78177792, start = 0

So it is seeing 4866 cylinders, 255 heads and 63 sectors.

I then ran "/sbin/lilo -v -v -v >/boot/lilo.log 2>/boot/lilo.logerr"
and got nothing back in the .logerr file (good) and the .log file
produced this for lilo:

******************************************

raid_setup returns offset = 00000000 ndisk = 0
BIOS VolumeID Device
Reading boot sector from /dev/hda
pf_hard_disk_scan: ndevs=1
0300 3DB012B3 /dev/hda
Resolve invalid VolumeIDs
Resolve duplicate VolumeIDs
0300 3DB012B3 /dev/hda
device codes (user assigned pf) = 0
device codes (user assigned) = 0
device codes (BIOS assigned) = 0
Filling in '/dev/hda' = 0x80
device codes (canonical) = 1
Device 0x0300: BIOS drive 0x80, 255 heads, 4866 cylinders,
63 sectors. Partition offset: 0 sectors.
Using serial number 3DB012B3 on bios 80
Device 0x0303: BIOS drive 0x80, 255 heads, 4866 cylinders,
63 sectors. Partition offset: 2216970 sectors.
Using serial number 3DB012B3 on bios 80
Warning: Unable to determine video adapter in use in the present
system.
Using MENU secondary loader
Calling map_insert_data
Secondary loader: 17 sectors (0x3200 dataend).
bios_boot = 0x80 bios_map = 0x80 map==boot = 0 map S/N: 3DB012B3
Mapping message file /boot/boot_message.txt
Device 0x0303: BIOS drive 0x80, 255 heads, 4866 cylinders,
63 sectors. Partition offset: 2216970 sectors.
Using serial number 3DB012B3 on bios 80
Calling map_insert_file
Message: 1 sector.
BIOS data check will include auto-suppress check

Boot image: /boot/vmlinuz -> vmlinuz-ide-2.4.26
Device 0x0303: BIOS drive 0x80, 255 heads, 4866 cylinders,
63 sectors. Partition offset: 2216970 sectors.
Using serial number 3DB012B3 on bios 80
Setup length is 10 sectors.
Mapped 2457 sectors.
Added Linux *
<dev=0xc0,hd=54,cyl=122,sct=29>
"ro root=303 hdc=ide-scsi"

BIOS VolumeID Device
80 3DB012B3 0300
Writing boot sector.
/boot/boot.0300 exists - no boot sector backup copy made.
Map file size: 26624 bytes.
RAID device mask 0x0000
Failsafe check: boot_dev_nr = 0x0300 0xffc0

************************************************** ********

which seems to indicate that lilo is seeing the same hard drive
geometry as linux (i.e. 4866/255/63).

I didn't see any obvious errors in dmesg after booting with the
Syslink boot disk, and the part relevant to hda is shown as:

************************************************** ********

hda: MAXTOR 6L040J2, ATA DISK drive
blk: queue c03b73e0, I/O limit 4095Mb (mask 0xffffffff)
hdc: LITE-ON LTR-24102M, ATAPI CD/DVD-ROM drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: attached ide-disk driver.
hda: host protected area => 1
hda: 78177792 sectors (40027 MB) w/1819KiB Cache, CHS=4866/255/63,
UDMA(100)
hdc: attached ide-cdrom driver.
hdc: ATAPI 40X CD-ROM CD-R/RW drive, 2048kB Cache, UDMA(33)
Uniform CD-ROM driver Revision: 3.12
Partition check:
hda: hda1 hda2 hda3
SCSI subsystem driver Revision: 1.00
kmod: failed to exec /sbin/modprobe -s -k scsi_hostadapter, errno = 2
kmod: failed to exec /sbin/modprobe -s -k scsi_hostadapter, errno = 2
kmod: failed to exec /sbin/modprobe -s -k scsi_hostadapter, errno = 2
md: linear personality registered as nr 1
md: raid0 personality registered as nr 2
md: raid1 personality registered as nr 3
md: raid5 personality registered as nr 4
raid5: measuring checksumming speed
8regs : 2288.400 MB/sec
32regs : 1466.800 MB/sec
pIII_sse : 2562.400 MB/sec
pII_mmx : 2286.000 MB/sec
p5_mmx : 2261.200 MB/sec
raid5: using function: pIII_sse (2562.400 MB/sec)
md: md driver 0.90.0 MAX_MD_DEVS=256, MD_SB_DISKS=27
md: Autodetecting RAID arrays.
md: autorun ...
md: ... autorun DONE.
LVM version 1.0.8(17/11/2003)
Initializing Cryptographic API
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP, IGMP
IP: routing cache hash table of 8192 buckets, 64Kbytes
TCP: Hash tables configured (established 262144 bind 65536)
Linux IP multicast router 0.06 plus PIM-SM
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
FAT: bogus logical sector size 0
UMSDOS: msdos_read_super failed, mount aborted.
FAT: bogus logical sector size 0
FAT: bogus logical sector size 0
reiserfs: found format "3.6" with standard journal
reiserfs: checking transaction log (device ide0(3,3)) ...
for (ide0(3,3))
ide0(3,3):Using r5 hash to sort names
VFS: Mounted root (reiserfs filesystem) readonly.
Freeing unused kernel memory: 120k freed
Adding Swap: 1044216k swap-space (priority -1)
Linux agpgart interface v0.99 (c) Jeff Hartmann
agpgart: Maximum main memory to use for agp memory: 690M
agpgart: Detected Intel i845 chipset
agpgart: AGP aperture is 64M @ 0xf8000000
scsi0 : SCSI host adapter emulation for IDE ATAPI devices

************************************************** *******

I have to admit, I don't know how to interpret the dmesg results. Any
obvious problems there?

And I did add LBA32 to my lilo.conf which is supposed to allow lilo to
bypass any cylinder limits on the hard drvie, but that didn't work
either.

I don't understand why lilo doesn't like the hard drive. Like I've
said, it's worked fine, I made no changes to lilo and then suddenly
the "LIL"... message popped up. Maybe I should consider using a new
loader (i.e. GRUB?). Or will doing something with "udev" help?

Thanks for your help,
Lucinda