Having trouble W/ Darg n Drop

hey.
I just got the resco keyboard skin and I am trying to do the vista theme on my ppc. I cannot drag the .png's from the vista theme to the resco kbd folder. (i can't cut and paste, I cant copy and paste, no drag and drop)
When I attempt to frag and drop, I get the circle with a line through it when go to other folder. What should I do?