I have a toshiba Portege 3505. I lost my tablet pen. I had purchased an extra when I bought the computer (same model pen right from toshiba). The eraser on the new pen does not erase. It functions the same as the drawing end. It will draw and move the cursor, and it will erase when the erase function is selected, but it won't do what the origina pen did. Erase no matter what the drawing end was doing. I have played with the pen setting, but can find no solution. Help