race condition finding devices for RAID group

During bootup, the disks are sometimes found and sometimes not. Attached is a failed boot (dmesg.0).

fdisk -L:
Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000080

   Device Boot Start End Blocks Id System
/dev/sda1 * 1 2432 19535008+ 83 Linux
/dev/sda2 2433 2918 3903795 82 Linux swap / Solaris
/dev/sda3 2919 60801 464945197+ fd Linux raid autodetect

Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000081

   Device Boot Start End Blocks Id System
/dev/sdb1 * 1 2432 19535008+ fd Linux raid autodetect
/dev/sdb2 2433 2918 3903795 82 Linux swap / Solaris
/dev/sdb3 2919 60801 464945197+ fd Linux raid autodetect

Disk /dev/sdc: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000082

   Device Boot Start End Blocks Id System
/dev/sdc1 * 1 2432 19535008+ fd Linux raid autodetect
/dev/sdc2 2433 2918 3903795 82 Linux swap / Solaris
/dev/sdc3 2919 60801 464945197+ fd Linux raid autodetect

Disk /dev/sdd: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000083

   Device Boot Start End Blocks Id System
/dev/sdd1 * 1 2432 19535008+ fd Linux raid autodetect
/dev/sdd2 2433 2918 3903795 82 Linux swap / Solaris
/dev/sdd3 2919 60801 464945197+ fd Linux raid autodetect