No income, sold primary home

[brandonlina]

My retired in-laws had not been filing income taxes for many years (no/low income). In 2010 they sold their primary home. Capital gain is less than 250,000 & they should be excluded from capital gain tax (own & use the home at 2 years of the last 5 years). The escrow company sent them a 1099S reporting the selling price of their home. Is it safe to say that they do not need to file 2010 income taxes (no/low income & capital gain is excluded)? Or are they required to file (even if there is no/low income & capital gain less than 250,000)?