upload size problem

CF7 file upload is failing validation when the file is greater than 2 MB in size. Using [file file-217 filetypes:mp3] had set limit but it was ignored so it was removed from the shortcode to test it hard coded: hard code changed the default limit to 4MB but it is ignored: files under 2mb are uploading, those over 2mb are rejected for validation error.. anybody have knowledge of this or perhaps maybe a fix..?..

http://ww.wp.xz.cn/plugins/contact-form-7/