jCover运行时敲回车出错“undefined”

Question

高手们小白遇见个问题，页面使用jcover来遮掩整个页面，同时显示请稍后…下面是代码
        $.jCover({                                                                                                        
                msg: "<img alt='' src='/img/indicator.gif' />&nbsp;<span style='white-space:nowrap;'>正在修改SNAT地址转换中，请稍候...</span>",
                msgCss: {                                                                                                 
                        background:"#ffffae",                                                                             
                        border : "solid 1px black",                                                                       
                        padding:"10px",                                                                                   
                        left:($(window).width()-160)/2,                                                                   
                        top:100                                                                                           
                }                                                              
        });                 
但是现在的错误在于，当“请稍后…”没消失时就按回车键或者空格键，”请稍后…”就会退出，同时有个弹窗“undefined”，有朋友说是jcover的错误，但是我实在没看出来哪儿错误了！有没有遇见同样情况的兄弟啊，是不是其他地方的错误啊，请指点下