To check again - did you examine the statue of the Virgin Mary and hear the comment about "her eyes that will illuminate"? The puzzle may not work correctly without hearing this.
MaG's walkthrough solution
HERE is described differently to Malcolm's, although you may have checked this already.
I can't recall this particular puzzle especially well, but would hazard a guess that the mirrors are set up so that they have to be tilted all the way in one direction before they are able to move back in the other direction to the required point, thus requiring 4 or 5 clicks?