Blowers

I just purchased a Poulan Pro PPBP30. I am very concerned about the reviews about the top engine mount failing. I have only used mine once and it worked perfectly. However, reviewers are stating the top engine mount breaks loose from the frame after the 2nd or third use. Can you explain to me why this is? Is this a design flaw? I have been a Poulan Pro fan for years and I don't want to be using my blower and the engine fall off the frame. Thank You.