There is a "Mouse" behavior that you can put on the box that will automatically set it to the cursor position.
But aside from that, what else are you trying to do with the box? Are there any other behaviors on it? Are there any events that conflict with your always event? Did you do something silly like put the code in a separate event sheet, then forget to include the event sheet in your layout events (I do this all the time)?
Barring any of those kinds of things, just upload your .cap so someone can take a look.