“While implementing a credit through reduced withholding is an effective way to provide economic stimulus evenly throughout the year, it is difficult to account for everyone’s circumstances,” said J. Russell George, the Treasury inspector general for tax administration. “More than 10 percent of all taxpayers who file individual tax returns for 2009 could owe additional taxes.”The tax credit is also available for 2010. Russell said the problems will continue in 2010 if they are not resolved.