ACL mask not preserved properly

[sorry if this is a repost.  I first sent it when I wasn't a member of 
the list and it appeared to have disappeared so am resending..]

I'm having a problem with star's handling of acl masks that I wanted to 
ask about.  The problem only happens on solaris (not linux) and it is 
happening with star-1.5a77.  Of course, we can't rule out operator error 
or Solaris bugs at this point.  All the gory details follow.

Star Version: 1.5a77.  Also tested with 1.5a76 and the same problem there.
Platform: Solaris 8/Sparc (I am not able to reproduce the problem on Red 
Hat EL4).
Summary: An ACL mask of rwx is not properly handled when the group 
permission is not rwx.  When the group permission is r-x the mask is 
changed from rwx to r-x.

This is probably best explained by an example:

1) I have two directories as follows:

# ls -l ../orig
total 2
drwxrwx---+  2 root          512 Apr  5 09:36 one/
drwxr-x---+  2 root          512 Apr  5 09:36 two/
# getfacl ../orig/one

# file: ../orig/one
# owner: root
# group: other
user::rwx
user:robh:rwx           #effective:rwx
group::rwx              #effective:rwx
mask:rwx
other:---
# getfacl ../orig/two

# file: ../orig/two
# owner: root
# group: other
user::rwx
user:robh:rwx           #effective:rwx
group::r-x              #effective:r-x
mask:rwx
other:---

The important thing to note is the mask of rwx on file "two".

2) I use star to tar up and then untar these directories as follows:

# star -version
star: star 1.5a77 (sparc-sun-solaris2.8)

Copyright (C) 1985, 88-90, 92-96, 98, 99, 2000-2007 J\uffffrg Schilling
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

# star -Hexustar -acl -c -C ../orig . | star -xp -acl one two
star: 1 blocks + 0 bytes (total of 10240 bytes = 10.00k).
star: 1 blocks + 0 bytes (total of 10240 bytes = 10.00k).

3) The acls are preserved on one but changed on two:

# ls -ld one two
drwxrwx---+  2 root          512 Apr  5 09:36 one/
drwxr-x---+  2 root          512 Apr  5 09:36 two/
# getfacl one

# file: one
# owner: root
# group: other
user::rwx
user:robh:rwx           #effective:rwx
group::rwx              #effective:rwx
mask:rwx
other:---
# getfacl two

# file: two
# owner: root
# group: other
user::rwx
user:robh:rwx           #effective:r-x
group::r-x              #effective:r-x
mask:r-x
other:---

Note that the mask on file two was changed from rwx to r-x.

This exact same test works as expected on Linux (RHEL4) so it is only 
Solaris that exhibits this problem.  If I create the tar file on the Sun 
and then extract it on the Linux machine it still fails so it seems like 
the problem is with the creation of the tar file on the Sun rather than 
the extract.  I'm trying to move a collection of user home directories 
from our old Solaris server to the new Linux server and want to preserve 
ACLs through the move.  Any feedback you can provide would be greatly 
appreciated.

Thanks,

  --Rob