Seems to have changed from OOO_STABLE_1, and now sets the object directory as if
MipsPro was been used, if gcc-2.95.3 is used (seems like it should work if gcc-3).
CVS access seems to be down at the moment, but the relevant section is:

$BIG_SVX = "TRUE";
if($USE_GCC3 eq "TRUE") {
    $COM  = "GCC";
    $OUTPATH = "unxirgm";
    $CVER = "C295";
} else {
    $COM   = "C730";
    $CVER  = "C730";
    $OUTPATH = "unxirxm3";
}

Which is obviously incorrect! It should look like this:
      $BIG_SVX        = "TRUE";
      if ($CC eq "gcc" ) {
              $COM          = "GCC";
              $OUTPATH        = "unxirgm";
              if ($USE_GCC3 eq  "TRUE") {
                $CVER           = "C295";
              } else {
                $CVER           = "C295";
              }
      } else {
        $COM            = "C730";
        $CVER           = "C730";
        $OUTPATH        = "unxirxm3";
      }