[Typo3-dev] clearCache for Back-End-Users whit clear_cacheCmd

[Thomas Janke]

hallo,

i have a small extension wich should enables several clear-cache-comands 
for backend-users.
i try to clear the cache with something like this:

$tce = t3lib_div::makeInstance('t3lib_TCEmain');

$tce->clear_cacheCmd(all);
or
$page_id_intval = intval( $page_id);
$tce->clear_cacheCmd($page_id_intval);

but the table cache_pages will not be cleared.

is there another reason why not-admin-users cannot clear the page cache 
in this way?

thanks for your help in advance.

greeting thomas