GEOM, gvinum, and SATA disks in standby

[D X]

After idling my gvinum RAID1 array using ataidle on a pair of WD Caviar
250GB SATA disks, I almost always get a READ_DMA timeout when trying to
access the disk (I'm guessing they take too long to spin up).

At this point one of 3 things will happen (which one it is seems random to
me at this point)

1. Both disks retry fine, and everything's great.  Unfortunately, this
happens about 1/3 of the time the disks come out of standby.
2. One of the disks retries fine, but the 2nd disk times out and gets
detached.  And I have a degraded array.  If I try to restart the downed plex
in gvinum, I get a kernel panic.
3. Both of the disks fail, my OS is partly hung, although I still get
responses to ping packets.  My console and terminals are dead though, as is
my httpd.  I usually end up rebooting in this case.

I saw a couple of posts online from last year mentioning similar issues.  Is
this a known bug that's going to be fixed anytime soon?