Yeah Chess Mentor stats are just meant to encourage you as a student. Useful to tell what courses need to be reviewed and chart your progress but little or no relation to your chess playing skill level. And there are ways to "game" the system to get an artificially high score as well (message me privately and I'll give you the post office box# to send the check to for secret methods). 
Chess mentor u craaaaazzzzy
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Depends on what lessons you do. If based on your Tactics rating, you are weak in tactics. Try the Tactics Section of Chess Mentor and your score would most probably go down.
Wouldn't you want the scores to go up? I mean because you were also training tactical motifs over at the Chess Mentor? Anyway I love those CM tactics courses. Coach Heisman has a whole "theory of chess learning" detailing the need to master basic tactics to the point where you can instantly recognize common patterns. He's alway recommending Bain's Chess Tactics For Students. One of his shows someone asked about what to set a tactics trainer for same range of difficulty as Bain. I think it was 900 to 1200 rated. So CM courses in the same range are ideal to start with if you're serious about improving.
I say, study whatever interests you.
http://puu.sh/cXJzg/beae34808c.png
How the hell...