WP internal Object Cache (not plugin)

Hi there,

I am running WordPress 2.8.5 (on Hostgator, sometimes it seems to be important!)

I have the following defined in wp-config.php

// caching
define ('ENABLE_CACHE',true);
define ('WP_CACHE', true);

I do have the folder “cache” under ‘wp-content’ (and it is chmod 644, the highest the hosting allows, but the processes are run as ‘owner’, so it is not the permissions issue)

And I do have the following code in my pages:

$mycache = wp_cache_get( 'mycache' );
if ($mycache == false) {
	$mycache = "this is mycache variable";
	$expire=60*30; // 60 seconds by 30 minutes
	wp_cache_set( 'mycache', $mycache ,'faces', $expire);
} else {
	// the cache has worked
	var_dump( $mycache );
}

And nothing happens. SO my question is – how does the WP Object cache operates? Can I use it in amy other way (for I am retrieveing remote pages and it is overly time consuming – and the retrieved pages do not change very often anyway)