I once encountered the same problem.
I then used $QUERYSTRING instead of $REQUEST_URI (works a bit different but maybe it's useful to you).
function stripqstring($feld="", $qstring="")
{
$felder = explode("&", $qstring);
$neu = array();
foreach($felder as $zuweis)
{
$zuweise = explode("=", $zuweis);
if($zuweise[0] != $feld)
array_push($neu, $zuweis);
}
$ret = implode("&", $neu);
return $ret;
}
Include this function in your script and do this:
$QUERYSTRING = stripqstring("offset", $QUERYSTRING);
This will remove the "offset" entry from your query string.