By default, tar is the Sun Solaris version of tar and
gtar is the GNU tar. Sun's version of tar is broken in
many ways in respect to the GNU version. By changing
the command to untar the files in the install script
from tar xzf to gtar xvf, the install worked perfectly
for me on Solaris 8 on an Sparc Ultra 1.
gtar should work on most other OSes because tar is
usually just an alias or a symlink to gtar.