Dedup issue

Hi,
I've been trying to test dedup on Solaris 11 as a guest to VirtualBox 4.1.6.
When VirtualBox was running on Windows Vista 64 all were OK, but when it was running on Solaris 10 U10 I've got the following strange thing:

v0002:~ # zpool status pool2
  pool: pool2
 state: ONLINE
  scan: none requested
config:

    NAME             STATE     READ WRITE CKSUM
    pool2            ONLINE       0     0     0
      mirror-0       ONLINE       0     0     0
        /var/tmp/d0  ONLINE       0     0     0
        /var/tmp/d1  ONLINE       0     0     0

errors: No known data errors

v0002:~ # ll /var/tmp/d?
-rw------T   1 root     root        128M Nov 18 10:54 /var/tmp/d0
-rw------T   1 root     root        128M Nov 18 10:54 /var/tmp/d1

v0002:~ # zpool get all pool2 | grep dedup