Images Not Appearing While Writing New Posts

hello every one,

i am running wordpress 2.9 from few days, it was working fine, i daily add new post to my wordpress and i daily need to add an image in my post…. but today i see some problem,

when i insert image into my wordpress both from url or upload from my pc, images are not showing in wordpress new post window, just a code is appearing… i clicked on HTML and tried inserting image, same happened, then i clicked on Visual, and tried to insert image same is happening….

here is a screen shot what happens when i insert image :

http://i45.tinypic.com/2vcx8d1.jpg

so please help me, return back to default settings which i used to insert image and i could see how it will look

thanks