config.php data-store cache affects style selection?

[OldSchoolDSL]

So every time I turn on this option within

Forum ROOT /includes/config.php

The menu option to switch themes / styles is completely gone. It's neither visible in the lower, left side or within user control panels.

PHP Code:

// ****** DATASTORE CACHE CONFIGURATION *****
    // Here you can configure different methods for caching datastore items.
    // vB_Datastore_Filecache  - to use includes/datastore/datastore_cache.php
    // vB_Datastore_APC - to use APC
    // vB_Datastore_XCache - to use XCache
    // vB_Datastore_Memcached - to use a Memcache server, more configuration below
$config['Datastore']['class'] = 'vB_Datastore_Filecache'; 


However, when I turn off this option.....

PHP Code:

// ****** DATASTORE CACHE CONFIGURATION *****
    // Here you can configure different methods for caching datastore items.
    // vB_Datastore_Filecache  - to use includes/datastore/datastore_cache.php
    // vB_Datastore_APC - to use APC
    // vB_Datastore_XCache - to use XCache
    // vB_Datastore_Memcached - to use a Memcache server, more configuration below
// $config['Datastore']['class'] = 'vB_Datastore_Filecache'; 


All is restored.

Thoughts?