well, for what it's worth, here's what I know:
i had a tutor who worked for Veritas, Kaplan and some other GMAT company. He told me (and apparently it was somewhat a confidential matter) that the makers of the test did a study on this myth and determined that spending more time on the first 10 questions will not help you in the end. In fact, it may even hurt you. Here's why - if you spend a lot a time on the first 10 to make sure you get them right, then you put yourself in a much harder bracket of questions that you have no business working through AND now you have less time to work on them.
The scoring on the GMAT is some mysterical science, but the first 10 questions do have an impact on the bank of questions you get - harder or easier.
Moral - the first 10 questions should be the easist if you are going to score high. But don't spend an unequal time on those questions.