A Death Sentence For Your Retirement SavingsBy Chuck JaffeBOSTON -- Jennifer W. is a single woman in her late 40s who is worried about her investment future and puzzled by her investment past.Like many people her age, she has been encouraged to save as much as possible through individual retirement accounts and 401(k) plans in order to grow her retirement nest egg. She started doing that as early as she could, with as much money as she had. Along the way, however, there were kids, a divorce, job loss and change. Couple some financial setbacks with 10 years of market volatility...