Most mortgage rates pretty much fell off a cliff during the week ending Oct. 23, according to a weekly survey by Freddie Mac (FRE), which found that the average 30-year fixed-rate mortgage was at 6.04 percent, down sharply from from an average 6.46 percent the previous week. "Long-term mortgage rates fell this week amid news of tame inflation and a weaker housing market," said Frank Nothaft, Freddie Mac vice president and chief economist. The average rate on a 15-year fixed-rate mortgage dropped as well, falling to 5.72 percent, down from the previous week's 6.14 percent, and slightly below the average a year ago this time. found similar easing in mortgage rates in its own weekly survey, which found that the benchmark for 30-year fixed-rate mortgages fell 42 basis points to an average of 6.32 percent for the week ending October 23. According to Freddie's data, five-year ARMs also dropped to 6.06 percent from the previous week's average of 6.14 percent, while one-year ARMs actually increased from 5.16 percent last week to 5.23 percent -- reflecting a shift in the yield curve. Prior to this week's report of easing rates, mortgage rates last week had experienced their biggest jump in 21 years. Much of that jump was erased this week, underscoring the volatility that has characterized mortgage rates since the early part of this year. "Mortgage rates' volatile behavior is part of the credit crisis," wrote Bankrate's Holden Lewis in weekly commentary. "There have been wide swings in various interest rates and bond yields in the last few months, and mortgages aren't immune." Editor’s note: To contact the reporter on this story, email