OCI8, OCINewDescriptor, OCIFreeDesc

[admin]

I have a problem.
I can't deletes a large object descriptor.
{begin code}
...

//the $userfile takes from the previous form
$f=fopen($userfile,"rb");
while(!feof($f))
{
$data .= fread($f,65000);
}
fclose($f);
...
$lob = OCINewDescriptor($Conn, OCI_D_LOB);
$stmt = OCIParse($Conn, $SqlInsert);
OCIBindByName($stmt, ':FILE_DATA', &$lob, -1, OCI_B_BLOB);
if (OCIExecute($stmt, OCI_DEFAULT) == false)
return 0;
if($lob->save($data))
OCICommit($Conn);
else
return 0;
if (OCIFreeDesc($lob) == false)
return 0;
...
{end code}
OCIFreeDesc($lob) always return false.
In what here a problem or a feature?