can't mount ext3 partition

[Matyas Matolcsi <madhat_(_at_)_ucla_(_dot_)_edu>]

[demime could not interpret encoding binary - treating as plain text]
* Apologies ahead of time if this comes out past 72 columns (webmail
client, so I can't control it)

Hello All, 

The Box: OpenBSD 3.5 on an AMD 5x86 133 with 64MB of EDO DRAM. The
harddrives are connected over a Promise ATA/66 card that is properly
recognized and initialized; the master drive holds the root partition,
and all of the slave drive is configured as a giant (relatively) ext3
partition. 

The Problem: Trying to mount that ext3 partition fails:

budapest# mount /dev/wd1d /mnt
mount_ext2fs: /dev/wd1d on /mnt: specified device does not match mounted device

There are some strange messages at the end of the dmesg about "Ext2 fs:
Unsupported optional feature"

Attempts: I've tried editing the disklabel and changing the partition's
letter assignment, but no luck (tried 'a' and 'd' so far.) The original
letter was 'i'. (peculiar -- why 'i'?) Also, I've updated /etc/fstab with 
the proper name, mount point, and file system options. (I read that this
is supposed to help fix it..., but no luck there either.)

Thanks to anyone who can help with this. I don't know much about the
*BSD's so this has been pretty frustrating. 

Infos:

The disklabel on this drive is:

budapest# disklabel wd1 
disklabel: warning, DOS partition table with no valid OpenBSD partition
# /dev/rwd1c:
type: ESDI
disk: ESDI/IDE disk
label: Maxtor 98196H8  
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 16383
total sectors: 160086528
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # microseconds
track-to-track seek: 0  # microseconds
drivedata: 0 

16 partitions:
#        size   offset    fstype   [fsize bsize   cpg]
  c: 160086528        0    unused        0     0        # (Cyl.    0 - 158815)
  d: 160071597       63    ext2fs                       # (Cyl.    0*- 158801*)

/etc/fstab:

budapest# cat /etc/fstab
/dev/wd0a / ffs rw 1 1
/dev/wd1d /home/archive ext2fs rw 0 0

budapest# dmesg
OpenBSD 3.5 (GENERIC) #34: Mon Mar 29 12:24:55 MST 2004
    deraadt_(_at_)_i386_(_dot_)_openbsd_(_dot_)_org:/usr/src/sys/arch/i386/compile/GENERIC
cpu0: AMD Am5x86 W/B 133/160 ("AuthenticAMD" 486-class)
cpu0: FPU
real mem  = 66699264 (65136K)
avail mem = 55750656 (54444K)
using 839 buffers containing 3436544 bytes (3356K) of memory
mainbus0 (root)
bios0 at mainbus0: AT/286+(00) BIOS, date 10/10/94, BIOS32 rev. 0 @ 0xf6f20
pcibios0 at bios0: rev. 2.1 @ 0xf0000/0x10000
pcibios0: PCI BIOS has 3 Interrupt Routing table entries
pcibios0: no compatible PCI ICU found
pcibios0: Warning, unable to fix up PCI interrupt routing
pcibios0: PCI bus #0 is the last bus
bios0: ROM list: 0xc0000/0x8000 0xc8000/0x1800
pci0 at mainbus0 bus 0: configuration mode 1 (bios)
pciide0 at pci0 dev 12 function 0 "Promise PDC20262" rev 0x01: DMA,
channel 0 configured to native-PCI, channel 1 configured to native-PCI
pciide0: using irq 10 for native-PCI interrupt
wd0 at pciide0 channel 0 drive 0: <WDC AC32100H>
wd0: 16-sector PIO, LBA, 2014MB, 4124736 sectors
wd1 at pciide0 channel 0 drive 1: <Maxtor 98196H8>
wd1: 16-sector PIO, LBA, 78167MB, 160086528 sectors
wd0(pciide0:0:0): using PIO mode 4, DMA mode 2
wd1(pciide0:0:1): using PIO mode 4, Ultra-DMA mode 4
pciide0: channel 1 disabled (no drives)
xl0 at pci0 dev 13 function 0 "3Com 3c905B 100Base-TX" rev 0x30: irq 11
address 00:10:5a:e6:24:58
exphy0 at xl0 phy 24: 3Com internal media interface
rl0 at pci0 dev 14 function 0 "Accton MPX 5030/5038" rev 0x10: irq 12
address 00:10:b5:5a:83:24
rlphy0 at rl0 phy 0: RTL internal phy
pchb0 at pci0 dev 16 function 0 "UMC UM8881F Host" rev 0x04
pcib0 at pci0 dev 18 function 0 "UMC UM8886" rev 0x0e
pciide1 at pci0 dev 18 function 1 "UMC UM8886BF" rev 0x10: DMA
(unsupported), channel 0 configured to compatibility, channel 1
configured to compatibility
pciide1: channel 0 ignored (not responding; disabled or no drives?)
pciide1: channel 1 ignored (not responding; disabled or no drives?)
isa0 at pcib0
isadma0 at isa0
pckbc0 at isa0 port 0x60/5
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard
vga0 at isa0 port 0x3b0/48 iomem 0xa0000/131072
wsdisplay0 at vga0: console (80x25, vt100 emulation), using wskbd0
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
pcppi0 at isa0 port 0x61
midi0 at pcppi0: <PC speaker>
sysbeep0 at pcppi0
lpt0 at isa0 port 0x378/4 irq 7
npx0 at isa0 port 0xf0/16: using exception 16
pccom0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo
pccom1 at isa0 port 0x2f8/8 irq 3: ns16550a, 16 byte fifo
biomask 400 netmask 1c00 ttymask 1c82
pctr: no performance counters in CPU
dkcsum: wd0 matched BIOS disk 80
wd1: no disk label
dkcsum: wd1 matched BIOS disk 81
root on wd0a
rootdev=0x0 rrootdev=0x300 rawdev=0x302
Ext2 fs: unsupported optional feature
Ext2 fs: unsupported optional feature