(Portland, OR)  --  Home prices are rising in Portland, but not as quickly as in other cities.  The S-and-P-Case-Shiller home price index puts Portland homes rising at a rate just below six-percent.  Double-digit home price increases are reported in Seattle, Las Vegas and San Francisco.  The national average is six-point-four-percent.  Brokers tell The Oregonian that the slowdown, amid a growing inventory, may mean Portland's hot real estate market is beginning to normalize.