After Mitt Romney agreed to release his tax return sooner rather than later, as he'd originally planned, Newt Gingrich responded with this:

I think it's exactly the right thing to do. And as far as I'm concerned, that particular issue is now set aside and we can go on and talk about other, bigger, and more important things.

Say what? He's going to release it on Tuesday. How is the issue now set aside when he hasn't done it yet? You haven't had the chance to scrutinize it and see if it contains any of the "problems" that you've been suggesting might be hiding in it while you called for it's release.

What this says to me is that Newt knows darned well that there's not going to be anything troublesome found in it, he didn't care whether he ever saw the tax return or not, and he was just using the whole issue for political advantage. Politics as usual.

Perhaps the reason Gingrich doesn't want to talk about Romney's tax return anymore is that dicussion of it would likely lead to this point (quoting from examiner.com)

Newt Gingrich has proposed setting taxes on income from investments to zero ... while the former Massachusetts governor supports eliminating capital gains taxes only for households with incomes under $200,000.

"My view is that we should not raise the capital gains tax but Speaker Gingrich thinks it should be taken to zero. And you recognize if we took the capital gains tax to zero then my taxes for instance instead of being 15% would be zero." Romney explained – as the presidential hopeful primarily lives off of returns from his investments rather than a salaried position on which he would pay income taxes.

"Mr. Millionaire Romney may be hiding something in his tax return" goes well with the sound of war drums. "I want to reduce Mr. Millionaire Romney's taxes to zero, while he wants to keep them at 15%" wouldn't play so well for Gingrich.