Have a Tax Question? Ask a Tax Expert
You will only have to file a return if your gross taxable income (excluding social security) including your taxable IRA distributions exceeds certain limits. If your filing status in 2008 is single then you only have to file a return if your gross income is $10,300 or more (if married filing jointly and your spouse is age 65 or older the income level is $20,000 or more).
See page 6 for 2007 filing requirements - http://www.irs.gov/pub/irs-pdf/i1040.pdf