NEW LOWS: Fixed mortgage rates fell this week to the lowest levels in six decades. The average rate for a 30-year loan hit 4.12 percent; the 15-year loan fell to 3.33 percent.

CAN'T CAPITALIZE: Most Americans can't take advantage of the low rates. Half of would-be buyers don't have enough for a down payment and shrunken home values have erased much of the equity people need to refinance.

SALES WEAK: The low rates have done little to energize sales of previously occupied homes, which are on pace for their weakest year since 1997.