Don't feel bad for using the hints. If you read M's intro, he says quite specifically that his intention is NOT to stump people -- because if it were, he would! Then, next to no one would be able to solve the problems.

The hints are there so normal people -- those of us who aren't hardcore about this sort of thing can do it too.

Currently I'm working on the musical notes problem in the archives... I haven't figured it out yet and I DON'T want to use the clues on that one.