Mortgage rates continued to slide this week, setting yet another record low, Freddie Mac (FRE) reported Wednesday -- sending refinancing applications through the roof. 30-year fixed-rate mortgages averaged an astoundingly low 5.10 percent with an average 0.7 point, down from 5.14 percent last week and 6.07 percent a year ago. “Interest rates for 30-year fixed-rate mortgages fell for the ninth straight week and represented a third consecutive all time record low since Freddie Mac’s survey began in April 1971,” said Frank Nothaft, Freddie Mac vice president and chief economist.  “Since the end of October of this year, these rates have declined by about 1-1/3 percentage points, or payment savings of approximately $173 a month for a $200,000 loan." Rates on 15-year fixed-rate mortgages also fell, averaging 4.83 percent with an average 0.7 point, down from last week's 4.91 percent, according to the GSE.  One-year Treasury-indexed ARMS followed the trend, falling to 4.85 percent from last week's 4.95 percent average. Five-year Treasury-indexed arms defied the falling tendency, and rose to 5.57 percent from 5.49 percent in the prior week, the report said. Falling rates are good news for potential buyers as “lower rates and falling house prices are...making homeownership more prices fell 18 percent over the 12-month period ending in October, according to the S&P/Case-Shiller® 20-city composite index...” Nothaft said. The Zillow Mortgage Rate Monitor, compiled each week using thousands of mortgage rates quoted on Zillow Mortgage Marketplace, also posted a drop in rates this week. Zillow's findings reported a drastically low 4.92 percent average for 30-year fixed mortgages.'s weekly mortgage rate survey, however, found that mortgage rates actually rose this week, following "near-record lows" in recent weeks.  The benchmark 30-year fixed-rate mortgage rose 42 basis points to 5.84 percent, Bankrate said Wednesday. "When lenders are deluged with loan applications (refi applications in this case), they sometimes raise rates until they catch up on the work," explained Bankrate's Holden Lewis. According to the MBA, total application volume was up 48 percent last week as refi applications surged almost 63 percent. Regardless of this week's conflicting rates reports, refis are indeed booming.  Read full story. Shore Mortgage, a Birmingham, Mich.-based Federal Housing Administration loan provider and mortgage company, announced Tuesday it would add 80 to 100 staff members, in order to manage the surge in applications -- predominately refis. Write to Kelly Curran at Disclosure: The author held no relevant investment positions when this story was published. Indirect holdings may exist via mutual fund investments. HW reporters and writers follow a strict disclosure policy, the first in the mortgage trade.