The screenshot shows you're pointing at a file on the D:\ that isn't your AddOns folder. I was under the impression that all custom textures used in kgPanels had to be in a path relative to your \Interface folder, or at the very least, your WoW folder. Is this incorrect?
EDIT: If that is the correct path, I believe it should be (starting with your Interface folder):
Interface\\AddOns\\myTextures\\WHaTeVeR.tga
EDIT2: Art Library -
http://www.wowace.com/addons/kg-pane...kg-panel-wiki/