Problem dumping one filesystem on a host

I'm having trouble backing up one particular filesystem on a host (FreeBSD
4.6-STABLE).  In particular, every time I run amdump, I get this result:

    FAILURE AND STRANGE DUMP SUMMARY:
      kanga.int  da0s1e lev 0 FAILED [disk da0s1e offline on kanga.int?]

Now, I've read the Amanda Faq-O-Matic entry for this error, but I still
can't see what's going on.  Here is the portion of my disklist file with the
relevant filesystems.  Note that the entry for da0s1e is identical to that
of ad0s1a except for the device name.

    # /
    kanga.int ad0s1a compressed-tar -1 local
    # /tmp
    kanga.int vinum/tmp compressed-tar -1 local
    # /home
    kanga.int vinum/home compressed-tar -1 local
    # /usr
    kanga.int vinum/usr compressed-tar -1 local
    # /usr/export
    kanga.int vinum/usr_export compressed-tar -1 local
    # /usr/obj
    kanga.int vinum/usr_obj compressed-tar -1 local
    # /usr/src
    kanga.int vinum/usr_src compressed-tar -1 local
    # /var
    kanga.int vinum/var compressed-tar -1 local
    # /usr/export/vserver2/home/freenet/store
    kanga.int da0s1e compressed-tar -1 local
    # Special large directories
    kanga.int /usr/share compressed-tar-with-excludes -1 local
    kanga.int /usr/share/media uncompressed-tar-with-excludes -1 local
    kanga.int /usr/share/media/music/all uncompressed-tar -1 local

Here are the log entries I'm getting, but they don't seem to say much:

    INFO planner Adding new disk kanga.int:da0s1e.
    INFO planner Incremental of pooh.int:volgroup1/usr_stripe32k bumped to 
level 2.
    INFO planner Incremental of pooh.int:volgroup1/var_stripe32k bumped to 
level 2.
    INFO planner Incremental of pooh.int:volgroup1/tmp_stripe32k bumped to 
level 2.
    INFO planner Incremental of kanga.int:vinum/home bumped to level 2.
    FAIL planner kanga.int da0s1e 20020815 0 [disk da0s1e offline on kanga.int?]

I've checked for permission problems, but ownership and perms are identical
on ad0s1a (which works correctly) and da0s1e (which fails):

    root@kanga:/var/amanda# ls -la /dev/ad0s1a /dev/da0s1e
    crw-r-----  2 root  operator  116, 0x00020000 Aug  9 10:41 /dev/ad0s1a
    crw-r-----  2 root  operator   13, 0x00020004 Aug  9 10:41 /dev/da0s1e

I've also fscked that partition without a change in the results:

    root@kanga:/var/amanda# umount /dev/da0s1e; fsck /dev/da0s1e; mount 
/dev/da0s1e
    ** /dev/da0s1e
    ** Last Mounted on /usr/export/vserver2/home/freenet/store
    ** Phase 1 - Check Blocks and Sizes
    ** Phase 2 - Check Pathnames
    ** Phase 3 - Check Connectivity
    ** Phase 4 - Check Reference Counts
    ** Phase 5 - Check Cyl groups
    9 files, 2098241 used, 2004845 free (13 frags, 250604 blocks, 0.0% 
fragmentation)

Finally, the drive itself is rather small (4GB), and the individual files
contained therein are not particularly large:

    root@kanga:/var/amanda# ls -al /usr/export/vserver2/home/freenet/store
    total 2098242
    drwxr-s---  2 1100  media        512 Aug 11 23:46 .
    drwx------  7 1100  media       1024 Aug 12 09:41 ..
    -rw-r--r--  1 1100  media  268435456 Aug 13 09:18 part0
    -rw-r--r--  1 1100  media  268435456 Aug 13 09:18 part1
    -rw-r--r--  1 1100  media  268435456 Aug 13 09:18 part2
    -rw-r--r--  1 1100  media  268435456 Aug 11 23:11 part3
    -rw-r--r--  1 1100  media  268435456 Aug 11 23:23 part4
    -rw-r--r--  1 1100  media  268435456 Aug 11 23:35 part5
    -rw-r--r--  1 1100  media  268435456 Aug 11 23:46 part6
    -rw-r--r--  1 1100  media  268435456 Aug 11 23:58 part7

I'm flummoxed.  I just can't see why I can't backup this filesystem, which
is indentical in many ways to other filesystems that get saved nightly.  Any
ideas what else I might look for?
-- 
Kirk Strauser
The Strauser Group - http://www.strausergroup.com/