Devices "removed from configuration"

[Blake Freeburg]

Hello,

  I added a new drive (one of the WD 180GB w 8MB cache) and installed it on the add-in PCI card (no problems, worked great).  After about two months, I wake one morning to my system paging me, and check the system; one of the drives has 'dissappeared' from the config.  It's in the machine, spinning, but not active.  Searching through the syslog, I find this:

May  3 00:00:00 davros /kernel: ad5s1e: hard error reading fsbn 105027655 of 52513796-52513799 (ad5s1 bn 105027655; cn 6537 tn 170 sn 40)ad5: timeout waiting for cm
d=ef s=11 e=04
May  3 00:00:00 davros /kernel: trying PIO mode
May  3 00:00:00 davros /kernel: ad5s1e: hard error reading fsbn 105027655 of 52513796-52513799 (ad5s1 bn 105027655; cn 6537 tn 170 sn 40) status=11 error=04
May  3 00:00:39 davros /kernel: ad5: timeout waiting for DRQ - resetting
May  3 00:00:39 davros /kernel: ata2: resetting devices .. 
May  3 00:00:39 davros /kernel: ad5: removed from configuration
May  3 00:00:39 davros /kernel: done

>From dmesg, I find that the drive was on a 
atapci1: <Promise TX2 ATA133 controller> port 0xcc00-0xcc0f,0xd000-0xd003,0xd400-0xd407,0xd800-0xd803,0xdc00-0xdc07 mem 0xcfffc000-0xcfffffff irq 5 at device 15.0 on pci0
ata2: at 0xdc00 on atapci1
ata3: at 0xd400 on atapci1

Finally, the system OS is:
FreeBSD davros.mrdata.com 4.6-STABLE FreeBSD 4.6-STABLE #0: Tue Aug 20 19:07:09 CDT 2002     ---- at davros.mrdata.com:/usr/obj/disk6/4.6-src/src/sys/MRDATA  i386

So, is there any way to recover from this?  Rebooting doesn't seem to 'bring the drive back'....

Sincerely,
Blake Freeburg
-- 
... esse quam videri