Reading Comprehension

Hi I scored 620 in my first Attempt and I am going to take second attempt of GMAT in next two weeks (10 Aug 2012), however my RC is not at all good. I am aiming for 700 + but the major obstacle in this seems to be RC. I don't know why I answer more than 50% of questions incorrect despite having a good understanding of whole content of passage. Can somebody please help me in the same?

Do you maintain an error log? What does your error log tell you?

A few points:
(1) Is there a particular type of RC question that troubles you the most? (Main Idea, Supporting Idea, Inference, Application..etc?). If so, focus more on those question types.

(2) If you asked me my age and I replied "I am not very old.", would my answer be of any help or relevance to you? Similarly, understanding the passage is one thing and using that understanding to answer what is asked is another. Are you understanding the questions equally well?

(3) Don't hunt for too many RC resources. Just do OG-13e and Verbal Review-2e; the questions therein are diverse enough. Spend enough time reviewing each question. (I CANNOT EMPHASIZE ENOUGH the importance of reviewing EVERY question, including those you get right). For example, if you got a question right, ask yourself why the other four choices did not seem right. Imagine yourself as a teacher who had to explain to his/her students why only one answer choice fits the bill perfectly and others don't.

Two weeks is good enough for you to do about 20 questions or 3 passages per day! Don't give up, don't loose your motivation. Just keep reviewing whatever your practice. Your mind should get trained to thinking the GMAT way in a fortnight's time.

All the best!