New image does not replace old one

I am using inserting images through a theme css file. The images are located in a child-folder images, in the file manager. I  overwrote one image but the old one still shows up however the new one is the one that shows up when you download. They are jpegs. 

Have you tried clearing your cache?  If the thumb\image name is the same the browser will have it cached.  The fact that the correct one downloads make me think this is the case...

Hi Steve,

how can i replace the image in image control with latest image dynamically in sitefinity.

Thanks,

pavan.