If you missed them the first time, here's your second chance. Mortgage rates last week tied historic lows, with the average 30-year fixed-rate mortgage bottoming out at 4.32 percent. A week earlier, the average rate was 4.37 percent; a year ago, rates hovered around 4.94 percent. Yet the purchase application index only rose 2.4 percent, according to the latest data. Exceptionally low loan rates do not appear to be having a meaningful impact on home sales, which have dropped off precipitously in recent months, due to factors such as unemployment and declining home values.