dloren4
I answered 32/41 correctly, 9 wrong and got a V34!! I also answered the first 12 correctly! I got 32/37 on Quant and a Q49, which is more reasonable than verbal but I felt should be Q50. Please before lecturing me on how difficult questions are worth more and first 10 are weighted heavier; this is 200 hours deep into study and 2 tests taken. I'm very familiar by now. I scored V39 on the real test and felt this should've been easily V41. I'm at a lost for an explanation besides the GMAC didn't put as much effort into their grading on practice exams compared to the real test.
I'm getting one more exam in before end of round 3 using a free voucher. Otherwise I wouldn't be dropping $250 to up a 720.
The GMATPrep software uses the same algorithm as the actual GMAT, and the exam packs are just databases with questions (so they don't have their own algorithm). Overall, the scoring of the exam packs is not as reliable as the scoring of the free tests, but that has more to do with the profile of the question pool than the "grading".
I suggest you look at your score as a range of scores. The V34 is not necessarily inaccurate. It could, however, be the case that most of your expected scores are more likely to be clustered around a higher score (like V39). This means that V34 could be rare for you (in which case you should keep in mind that every test taker is likely to perform below his or her potential on at least one practice test, and maybe even on the actual exam).