Problem with custom component for SEF Advanse

I am using SEF Advanse component.
And have some problems.

I try to use SEF Advanse extension  for my component com_example
So I inserted sef_ext.php to directory components/com_example/
Here is components/com_example/sef_ext.php content:
<?php
class sef_example {
function create ($string) {
// $string == "index.php?option=com_example&Itemid=$Itemid&var1=$var1&var2=$var2"
$sefstring = '';
if (eregi('&var1=',$string)) {
$temp = explode('&var1=', $string);
$temp = explode('&', $temp[1]);
$sefstring .= sefencode($temp[0]).'/';
}
if (eregi('&var2=',$string)) {
$temp = explode('&var2=', $string);
$temp = explode('&', $temp[1]);
$sefstring .= sefencode($temp[0])."/";
}
return $sefstring;
}
function revert ($url_array, $pos) {
if (( ini_get('register_globals')==1 && (!defined('RG_EMULATION') || RG_EMULATION==1) ) ||
( ini_get('register_globals')==0 && (defined('RG_EMULATION') && RG_EMULATION==1) ) ) {
global $var1, $var2;
}
$QUERY_STRING = '';
if (isset($url_array[$pos+2]) && $url_array[$pos+2]!='') {
$var1 = sefdecode($url_array[$pos+2]);
$_GET = $_REQUEST = $var1;
$QUERY_STRING .= "&var1=$var1";
}
if (isset($url_array[$pos+3]) && $url_array[$pos+3]!='') {
$var2 = sefdecode($url_array[$pos+3]);
$_GET = $_REQUEST = $var2;
$QUERY_STRING .= "&var2=$var2";
}
return $QUERY_STRING;
}
}
?>
Here is components/com_example/example.php content:
<?php
defined( '_VALID_MOS' ) or die( 'Restricted access' );
echo 'start debug example component';
print_r($_GET);
?>

I tryed go to dev.accuscore.com/index.php?option=com_e...=4&var1=aaa&var2=bbb
and it redirected me to dev.accuscore.com/

Then I switch on Debug: 'yes' in admin area Sef component.
When I try to go  dev.accuscore.com/index.php?option=com_e...=4&var1=aaa&var2=bbb
now, system redirect me to dev.accuscore.com/example/aaa/bbb/
But page displays "You are not authorised to view this resource."

Can you help me please?
May be to do something in in admin area Sef component?