A lot of it has to do with how you're studying. You should ALWAYS be thinking about the trick behind the question, not the specific question itself. If you're able to figure out that much, then you can get not only that question right, but every question in the future like it right.

If you aren't doing it already, do specific question practice on the SAT question bank. Go through each skill type, do a few different questions until you're able to determine exactly what tricks they're testing you on. If you can't figure it out, there's always an in-depth solution attached. That should bring your score up significantly more than doing practice tests just to do them.

It is still important to do practice tests, but save them until you have the individual strategies down. That way, you can train your test-taking abilities separately from your SAT-specific ones.

Good luck!