What are they hiding?

Hillary Clinton and John McCain won't release their income tax returns. In "Show us the money" the NY Times (!) notes that for Hillary this is particular problem because she loaned her own campaign $5 million:

The need for greater transparency regarding the income and overall financial dealings of candidates and their spouses was underscored by Mrs. Clinton's recent decision to make a $5 million loan to her campaign. Such borrowing is a permitted practice under the campaign laws. But the campaign said the money came from her share of the Clintons' joint resources, and that calls attention to the lack of information about their family finances. As a former president, Bill Clinton has been making millions annually giving speeches and traveling the globe. What is publicly known about his business dealings is sketchy, and clearer disclosure of them is required to reassure voters that Mrs. Clinton's candidacy is unencumbered by hidden entanglements.

As something of an investigative body, isn't the Times at least a little embarrassed to describe Bill Clinton's quid pro quo business dealings as "sketchy?" In fact, they have been well-documented by Newsweek and - whoops - the New York Times. Hillary claims that her money comes from sales of her autobiography and that's fine; so why all the secrecy?