I had a clue that required me to wear a legend'scape and excaliber sword while digging in the range guild. After killing the Zamorakian (sp) I dug again and my clue disappeared. I did get the message "congratulations you completed the treasure trail", but I didnt get any rewards. I dug again and the zamorakian appeared again. I repeated the process 3 times with no rewards (still got the "congratulations" message each time and the zamorakian keeps popping up.