Hi,

The pool of GMAT questions is constantly being updated from the people at GMAC. This is why not all of the questions that appear on the test actually count towards your final grade. Some of the questions are being tested and calibrated in order to finally have them become 'active' questions in the pool. I believe that the OG questions are simply lists of retired questions from the question bank, and so there is essentially ZERO chance of seeing an OG question on the real test.

Indeed the GMAC are very precious about their live questions and I have heard of multi million dollar lawsuits against websites that have allowed live questions to be posted.

I would say that the best thing to do is not worry about it too much and focus on techniques and skills.

Hope that helps.