Those dumb rebate checks are causing problems - still!
Since the credit was originally based on the taxpayer's 2008 tax return and advanced based info from the 2007 return, the credit is being re-figured this year. If the taxpayer qualifies for more, credit it is added to the refund or reduces the balance due.
But the IRS is having problems with returns where the credit is being figured incorrectly and the taxpayers saying they qualify more money. If you are not sure you qualify for the Recovery Rebate Credit on your 2008 return you can do nothing and the IRS will figure it for you and send you any extra money. But that may delay your refund. Or you can go to the IRS' "How Much Rebate" web page and check for your self. The IRS has said that returns with the wrong prior year rebate will require extra processing and take longer.