Help Removing Frame On Linked Images

Hi

I am using a theme called Chun its a very good theme but it has this large grayish frame around images that have links attached (i.e you click them to go to another page)the frame is very light in colour when you dont put the mouse over it but becomes darker when the mouse goes over it. Either way I want the frame gone because I have rounded images I want to run into the white background. I have been looking it up online and tried just about anything I could see. Does someone with experience of this paticular theme or problem have a workable solution. Example of the image problem can be seen here http://www.conorbennett.com at the bottom three images

Thanks