$result = $db_con->query(\"SELECT SQL_CALC_FOUND_ROWS * FROM users LIMIT 0,10\");
$count_result = $db_con->query(\"SELECT FOUND_ROWS() as totalcount\");
$row
LIMIT
is required to make found_rows() work correctly
Add a LIMIT to the end of your query, ie.
SELECT SQL_CALC_FOUND_ROWS * FROM users LIMIT 0,10;
http://dev.mysql.com/doc/refman/5.0/en/information-functions.html#function_found-rows
FOUND_ROWS()
-- For a SELECT with a LIMIT clause, the number of rows that would be returned were there no LIMIT clause