Romney said taxes, not Federal Income Taxes or Federal Taxes. Looking at his returns for 2010, one sees that in 2008 he paid $787,455 in foreign taxes.
In 2010 he paid $672,444 in state taxes, and $226,356 in real estate taxes.
Given that there must have been heavy investment losses in 2008 (and 2009), and that his Bain income probably decreased, why yes, it is possible that he paid no Federal Income Tax and still paid ~13% of his (lower 2008/9) income in overall taxes.
The pattern of his foreign taxes is also interesting
Passive General
2000 $31,838
2001 $25,771
2002 $28,875
2003 $11,173
2004 $87,550
2005 $333,149
2006 $276,386
2007 $275,488 $148,510
2008 $151,015 $636,440
2009 $81,461 $56,891
2010 $67,173 $690
Passive income refers to income from interest and dividends, general would include selling of stocks or bonds and from the pattern it looks like Mitt cashed out in 2008, maybe at the top of the market before it crashed.
his 2008 and 2009 returns are obviously key and we need to see them.