In this section of the walkthrough by Tally Ho (which you can find here on GameBoomers) it mentions making sure you don't have any other numbers illuminated. I have played this game but since I cannot see the puzzle or remember it well enough, I'm not sure what that means, but hopefully you can figure it out. Do you have some other number illuminated that shouldn't be?
"Now, for building the constellations - you must get all four numbers of the desired coordinate onto the same row. It can be any one of the four rows, but they do not have to be in sequence. Rotate the golden ball so that it indicates the row you have assembled. Then look in the telescope. If you have aimed it at a constellation, it will be visible. Then select the appropriate star to illuminate the one correct number.
The four sets of numbers you must use are:
86, 59, 73, 68. The Mermaid. Select 73 in the scope.
11, 47, 32, 95. The Minotaur. Select 47.
62, 33, 46, 25. The Manticor. Select 33.
87, 25, 68, 95. The Griffin. Select 87.
Careful - you must not have any other numbers illuminated except those four. When you get it right, you receive an object for your efforts."