Correct use of zend_list_delete

Maybe this is a question too simple for this list, but I am writing
my first php extension (using php 4.4 SDK) so please, be patient...
My extension (rsql) returns a custom struct to php so my code in my
rsql_connect looks like:

ZEND_FUNCTION(rsql_connect)
{
....
RETURN_RESOURCE(zend_list_insert(rsqldb, rsql_connection));
}

The relevant code is:

ZEND_FUNCTION(rsql_disconnect)
{
...
ZEND_FETCH_RESOURCE2(rsqldb, void*, theConnectionParameter, -1,
kConnIDString, rsql_connection, rsql_pconnection);
if (rsqldb) zend_list_delete(Z_LVAL_PP(theConnectionParameter));
if (rsqldb) myCustomFree(rsqldb);
}

static void rsql_realconnectionclose(zend_rsrc_list_entry *rsrc)
{
void *rsqldb;
if (rsrc != NULL)
{
rsqldb = rsrc->ptr;
if (rsqldb != NULL)
{
rsqlserver_disconnect(rsqldb, kTRUE);
rsqldb = NULL;

		if (persistent == kTRUE)
			RSQL_G(num_persistent)--;
	}
}

}

PHP_MINIT_FUNCTION(rsql)
{
rsql_connection = zend_register_list_destructors_ex
(rsql_realconnectionclose, NULL, kConnIDString, module_number);
}

What is the issue I encounter with this code?
This php code crashes:

for ($i=0; $i<10; $i++){

$dbconn = rsql_connect("127.0.0.1","admin","admin");
if (is_resource($dbconn) == 0){
	print "Connection to database server failed.";
	exit();
}

rsql_disconnect($dbconn);

}

and also this one:

for ($i=0; $i<10; $i++){

$dbconn = rsql_connect("127.0.0.1","admin","admin");
if (is_resource($dbconn) == 0){
	print "Connection to database server failed.";
	exit();
}

}

What I think is that when rsql_disconnect is called explicitly or by
the destructor (rsql_realconnectionclose) my custom struct isn't
really deleted from the zend_list.

I really appreciate any help for my issue...

Thanks a lot,
Marco Bambini