Incompatibility with PHP Zlib module

CKFinder 2.0.2 PHP
/ckfinder/core/connector/php/php4/CommandHandler/Thumbnail.php
/ckfinder/core/connector/php/php5/CommandHandler/Thumbnail.php
Line 46-48

        while (ob_get_level()){
            ob_end_clean();
        }

Function "ob_end_clean" can not delete buffer of zlib output compression.
Because of this, function "ob_get_level" always returns 1, which causes an infinite loop and no thumbnails.

Zlib is quite popular PHP library, so it should be taken into account.