@karanamin,
No, the questions in the database of the Computer adaptive tests do not change on downloading the GMATPrep question pack 1. However, if you were to repeat the practice tests you will get a different set of questions, although there would be some repeats.
Your only option is to retake the 2 CATs, there will be some overlap with your first attempt(little to none, it depends), and your scores would be somewhat biased, but I still think it is a valuable exercise to retake each of those practice tests for a total of three times. I wish GMAC would release a set of 6 full length tests, but that is unfortunately not the current reality.
The other option would be to take the three diagnostic tests that are part of the GMATFocus available from mba.com.