CodeIgniter使用Ckeditor+Ckfinder的问题！

Question

//index.html

<h4 align="center">编辑文章</h4>
<div class="control-group">
<textarea name="contents"></textarea>
<span class='text-success'></span>
</div>
                    <script src="<?php echo base_url('public/ckeditor/ckeditor.js');?>"></script> 
                    <script>
                    CKEDITOR.replace( 'contents', {
                    filebrowserBrowseUrl:'<?php echo base_url();?>public/ckeditor/ckfinder/ckfinder.html',          
                    filebrowserImageBrowseUrl : '<?php echo base_url();?>public/ckeditor/ckfinder/ckfinder.html?Type=Images',         
                    filebrowserFlashBrowseUrl : '<?php echo base_url();?>public/ckeditor/ckfinder/ckfinder.html?Type=Flash',         
                    filebrowserUploadUrl : '<?php echo base_url();?>public/ckeditor/ckfinder/core/connector/php/connector.php?command=QuickUpload&type=Files',
                filebrowserImageUploadUrl:'public/ckeditor/ckfinder/core/connector/php/connector.php?command=QuickUpload&type=Images',
            filebrowserFlashUploadUrl:'<?php echo base_url();?>public/ckeditor/ckfinder/core/connector/php/connector.php?command=QuickUpload&type=Flash'});
                    </script> 

        //ckeditor/config.js
        CKEDITOR.editorConfig = function( config ) {
            config.language = 'zh-cn';
            config.toolbar = 'Rich';
            config.toobar_Rich = [
                ['Source','-','Format','Styles','FontSize'],
                ['Outdent','indent','Blockquote'],
                ['TextColor','BGColor'],
                ['Link','Unlink','Anchor'],
                ['Templates','Preview'],
                ['showBlocks','Maximize'],
                '/',
                ['RemoveFormat','Undo','Redo','-','Bold','Italic','Underline','Strike'],
                ['Subscript','Superscript','NumberedList','BulletedList'],
                ['JustifyLeft','JusrifyCenter','JnstifyRight','JustifyRight','JusrifyBlick'],
                ['PageBreak','Table','HorizontalRule','Smiley','SpecialChar','-','wpMore','image']
            ];
            config.uiColor = '#AADC6E';
            config.width = 1000;
            config.height = 300;
            config.disableNativeSpellChecker = false;
            config.scayt_autoStartup = false;
            config.font_names = '宋体/宋体;黑体/黑体;仿宋/仿宋_GB2312;楷体/楷体_GB2312;隶书/隶书;幼圆/幼圆;'
        };

        //php/php.ini
    memory_limit=500M
    post_max_size=500M

为什么数据量一大post就取不到值了呢？
如果是一张图片，或者一串文字post可以正常取到值，
但如果10张图片加1000文字post返回空！
是我哪边没配置好吗？