This from factcheck.org:
President Bush himself would have qualified as a "small business owner" under the Republican definition, based on his 2001 federal income tax returns. He reported $84 of business income from his part ownership of a timber-growing enterprise. However, 99.99% of Bush's total income came from other sources that year. (Bush also qualified as a "small business owner" in 2000 based on $314 of "business income," but not in 2002 and 2003 when he reported his timber income as "royalties" on a different tax schedule.)
Meanwhile, those watching the debates, including Kathryn General, probably believed that Kerry was full of it when he made that assertion. What a sad sad world.