The charm window probably is opening off screen. Were you using the exploit in the unpatched game that lets you open multiple charm windows? This problem can also be caused by opening a charm window near the edge of the screen and later reducing the game resolution, but since you are at the maximum of 1024x768, that wouldn't be the case here.
Edit the config.div file (in Notepad or another text editor) to temporarily play at a higher resolution, such as 1280x1024. Note: the game itself may be fine at higher than supported resolutions, but opening the auto-map can cause the game to crash. After you change the resolution and save, start the game, open a charm window, move it into the center of the screen and close it. Quit, either edit the config.div file again or run the configuration program and restore the original resolution; now when you re-start, the charm windows should open on screen.