Ok correct. But is it not better than:
$cache->remove_file('sql_' . md5($cached) . '.' . $phpEx);
in socialnet/acp/acp_im.php? 
I see the remove_file() the first time.


I think the remove_file() is not working there, the SQL query will be trimmed, before the md5 will generate.
You need too add this line: (socialnet/acp/acp_im.php)
$cached = preg_replace('/[\n\r\s\t]+/', ' ', $cached); // from acm_file.php
before:
$cache->remove_file('sql_' . md5($cached) . '.' . $phpEx);