Newt is a tax cheat. The code is complex and Forbes breaks it down clearly. I won't recreate their work here, just quote the conclusion.
...in 2010, the Gingrich corporations paid out $444, 327 as salary to Newt and Callista while reporting some $2.4 million as profit or dividends – thus allowing the Gingrichs to avoid paying the 2.9 percent Medicare tax on the bulk of their earnings.
Of course, now that Gingrich is running for president, it is unlikely the IRS will come after him as he would simply call it an attack by the Obama administration.
Boy did the right wing talking heads bang on about the tax cheating ways of Daschle and Geithner, but we can expect them to carry water for Gingrich on this issue as well. Apparently the True Conservatives (c) only get upset when it is a democrat who cheats on his wife or his taxes.