Problems using AMD automounter on BETA7

Hi.

I have found a very strange behavior on using the external USB-HDD 
and automounting it under BETA7.

In general it works fine, but yesterday late evening I was moving a lot
of relatively small files beween 2 partitions on this drive.
Some time later I looked at the first terminal and noted there a few pages
of messages like:

Oct 15 01:29:53 kvip55 kernel: fsync: giving up on dirty: 0xc258c630: tag 
devfs, type VCHR, usecount 6, writecount 0, refcount 5, flags (VV_OBJBUF), 
lock type devfs: EXCL (count 1) by thread 0xc2732af0 (pid 1012)
Oct 15 01:29:53 kvip55 kernel: dev da0s2a
Oct 15 01:29:53 kvip55 amd[352]: /amd/d2: unmount: Resource temporarily 
unavailable

/amd/d2 is a ufs partition mounted from da0s2a

In the same time the copying itself went smooth.
BTW, is it enough to just dismount partition to make it flush all 
buffers before switching the HDD off ?
And is it also holds for the msdos_fs, as this one can't be mounted
in sync mode ?

-- 
Best regards,
  Alexander.