Let them eat the one tax return we gave you people

Mrs Willard Romney is supposed to be the nice Romney, she polls better than Willard, she has a higher favorability rating then Willard. 

Seventy one percent of Americans say they wouldn't trust Willard to watch their dog.

But not so with Mrs Willard.  She's beloved by all her sons and at least half of her daughters-in-law. Forty eight percent of Americans say they would allow Mrs Willard to watch their dog as long as she promised not to let her husband tie the dog to the roof of one of her nineteen Cadillacs.

So it's surprising that Mrs Willard got all snarky when a reporter asked about the Romney tax returns, now hidden in the tax return witness protection program.  She said there weren't going to be any more tax returns released. 

Why?  What's the problem? 

Off-shore bank accounts?  Hidden assets?  Low or no taxes?  Swiss bank account amnesty from the IRS?