I have the same problem, won't recognize he RAID 1 array on my ICH9R, (Intel X48, Gigabyte X48T-DQ6)  warm reboot gives "member offline" for both member disks, but a cold reboot restores them to normal operational status.  Using 8.04 Live CD.  This RAID works fine under Windows.

A similar problem is discussed in this thread: http://osdir.com/ml/linux.ataraid/2007-09/msg00019.html

Here's my info, let me know if anything else would be useful:

ubuntu@ubuntu:~$ sudo dmraid -ay
ERROR: isw device for volume "RAID" broken on /dev/sdc in RAID set "isw_bfhebdcdbd_RAID"
ERROR: isw: wrong # of devices in RAID set "isw_bfhebdcdbd_RAID" [1/2] on /dev/sdc
ERROR: isw device for volume "RAID" broken on /dev/sdb in RAID set "isw_cajggdbbad_RAID"
ERROR: isw: wrong # of devices in RAID set "isw_cajggdbbad_RAID" [1/2] on /dev/sdb
ERROR: no mapping possible for RAID set isw_bfhebdcdbd_RAID
ERROR: no mapping possible for RAID set isw_cajggdbbad_RAID

ubuntu@ubuntu:~$ sudo dmraid -b
/dev/sdc:    976773168 total, "9QM0KAPS"
/dev/sdb:    976773168 total, "9QM0K9QQ"
/dev/sda:    488397168 total, "9SF03FRH"

# sda is my boot disk, and is not a member of the RAID

ubuntu@ubuntu:~$ sudo dmraid -n
/dev/sdc (isw):
0x000 sig: "  Intel Raid ISM Cfg Sig. 1.1.00"
0x020 check_sum: 1693590363
0x024 mpb_size: 480
0x028 family_num: 1574132313
0x02c generation_num: 4466
0x030 reserved[0]: 4080
0x034 reserved[1]: 2147483648
0x038 num_disks: 2
0x039 num_raid_devs: 1
0x03a fill[0]: 2
0x03b fill[1]: 0
0x040 filler[1]: 1574132313
0x0d8 disk[0].serial: "        9QM0K9QQ"
0x0e8 disk[0].totalBlocks: 976771055
0x0ec disk[0].scsiId: 0x20000
0x0f0 disk[0].status: 0x53a
0x108 disk[1].serial: "        9QM0KAPS"
0x118 disk[1].totalBlocks: 976773168
0x11c disk[1].scsiId: 0x30000
0x120 disk[1].status: 0x53a
0x138 isw_dev[0].volume: "            RAID"
0x14c isw_dev[0].SizeHigh: 0
0x148 isw_dev[0].SizeLow: 976764928
0x150 isw_dev[0].status: 0xc
0x154 isw_dev[0].reserved_blocks: 0
0x158 isw_dev[0].filler[0]: 1900544
0x190 isw_dev[0].vol.migr_state: 0
0x191 isw_dev[0].vol.migr_type: 0
0x192 isw_dev[0].vol.dirty: 0
0x193 isw_dev[0].vol.fill[0]: 255
0x1a8 isw_dev[0].vol.map.pba_of_lba0: 0
0x1ac isw_dev[0].vol.map.blocks_per_member: 976765192
0x1b0 isw_dev[0].vol.map.num_data_stripes: 3815488
0x1b4 isw_dev[0].vol.map.blocks_per_strip: 128
0x1b6 isw_dev[0].vol.map.map_state: 0
0x1b7 isw_dev[0].vol.map.raid_level: 1
0x1b8 isw_dev[0].vol.map.num_members: 2
0x1b9 isw_dev[0].vol.map.reserved[0]: 2
0x1ba isw_dev[0].vol.map.reserved[1]: 255
0x1bb isw_dev[0].vol.map.reserved[2]: 1
0x1d8 isw_dev[0].vol.map.disk_ord_tbl[0]: 0x0
0x1dc isw_dev[0].vol.map.disk_ord_tbl[1]: 0x1

/dev/sdb (isw):
0x000 sig: "  Intel Raid ISM Cfg Sig. 1.1.00"
0x020 check_sum: 2738587652
0x024 mpb_size: 480
0x028 family_num: 2096631103
0x02c generation_num: 6
0x030 reserved[0]: 4080
0x034 reserved[1]: 2147483648
0x038 num_disks: 2
0x039 num_raid_devs: 1
0x03a fill[0]: 2
0x03b fill[1]: 0
0x040 filler[1]: 2096631103
0x0d8 disk[0].serial: "        9QM0K9QQ"
0x0e8 disk[0].totalBlocks: 976773168
0x0ec disk[0].scsiId: 0x20000
0x0f0 disk[0].status: 0x13a
0x108 disk[1].serial: "        9QM0KAPS"
0x118 disk[1].totalBlocks: 976773168
0x11c disk[1].scsiId: 0x30000
0x120 disk[1].status: 0x13a
0x138 isw_dev[0].volume: "            RAID"
0x14c isw_dev[0].SizeHigh: 0
0x148 isw_dev[0].SizeLow: 976766976
0x150 isw_dev[0].status: 0xc
0x154 isw_dev[0].reserved_blocks: 0
0x158 isw_dev[0].filler[0]: 1900544
0x190 isw_dev[0].vol.migr_state: 0
0x191 isw_dev[0].vol.migr_type: 0
0x192 isw_dev[0].vol.dirty: 0
0x193 isw_dev[0].vol.fill[0]: 255
0x1a8 isw_dev[0].vol.map.pba_of_lba0: 0
0x1ac isw_dev[0].vol.map.blocks_per_member: 976767240
0x1b0 isw_dev[0].vol.map.num_data_stripes: 3815496
0x1b4 isw_dev[0].vol.map.blocks_per_strip: 128
0x1b6 isw_dev[0].vol.map.map_state: 0
0x1b7 isw_dev[0].vol.map.raid_level: 1
0x1b8 isw_dev[0].vol.map.num_members: 2
0x1b9 isw_dev[0].vol.map.reserved[0]: 2
0x1ba isw_dev[0].vol.map.reserved[1]: 255
0x1bb isw_dev[0].vol.map.reserved[2]: 1
0x1d8 isw_dev[0].vol.map.disk_ord_tbl[0]: 0x0
0x1dc isw_dev[0].vol.map.disk_ord_tbl[1]: 0x1

ubuntu@ubuntu:~$