delete error

hello ereryone when i delete a post or a page,the wp tell me there is something err(see the printscreen here http://www.23hq.com/frnong/photo/348063 or http://photo3.yupoo.com/20060112/20060112095206_1749390949_o.jpg)

but it was did not influence anything else(I can post,edit,even i can delete the post or page when I reflesh the page)

is there anyone can tell me why this happen?Thanks a lot