Don't fall off your breakfast stool: At least one housing analysis claims that Tampa Bay homes are 20 percent undervalued. So says IHS Global Insight in a report, using statistics culled at the end of last year, titled House Prices in America. IHS said Tampa Bay home prices were 30.2 percent overvalued at the end of 2005 but had overcorrected by falling to $120,000 by the end of 2009. IHS determined correct valuation by studying not just home prices and interest rates, but also household income, population density and historical premiums and discounts paid for Tampa Bay housing. Other hard-hit markets like Las Vegas and Fort Myers also placed near the top of the "undervalued" column. IHS didn't give full weight to foreclosures and unemployment, which probably accounts for why prices here are $24,000 less than the report said they should be.